2 Flashcards
Identity, 2 subtypes of identity
How we view ourselves
- personal identity
-
social identity
- usually what is being discussed
Identity can be
negotiated and contested
- This allows people to apply identities/labels to people who may disagree
Forms of Identity
- Age
- Race: based on physical characteristics
- Ethnicity: refers to ones cultural background
- Nationality: political and legal concept independent of race and ethnicity
Gender Identity:
Sexual orientation
- sexual vs. romantic orientation
how people perceive themselves relative to social categories masculinity and femininity
-
Gender is a social construct
- cisgender: gender matches sex
- transgender: gender distinct from sex
- Sex is a biological category
Sexual orientation: who people are attracted to as sexual partners
- homosexual: same sex
- heterosexual: opposite sex
- bisexual: both
- pansexual: all sexes
Sexual vs. romantic orientation: asymmetry between who someone wants to be a sexual partner and a romantic partner
Categories of Identity
Socioeconomic class
Religion
- the relative importance, or salience, of these categories differ among people and societies
Development of identity
Social Factors
Input about who they are themselves and how they relate to others
Explicit input: someone telling them something
Implicit input: observed behaviors
Socialization shapes gender norms, roles, and identity
Theories on Identity: Freud’s Pyschosexual Perspective
Conflicts or complexes acquired in various developmental stages can impact someone’s identity
Theories on Identity: Kohlberg’s Theory of Moral Development
6 stages
Morality in the light of social conventions can shape political identity and sense of self
Looking-Glass Self Concept
Our perceptions about how other people see us shapes how we see ourselves
- people send us explicit and implicit messages about how they perceive us
George Herbert Mead (1902)
Role Model
How children internalize and imitate examples set by adults in their surroundings
Role Playing (Role Taking)
Who?
George Herbert Mead (looking glass self)
Essential to inhabiting and understanding others perspectives
- child games help replicate social expectations regarding roles in society
- end point of this process is targeted toward the self
Impression Management
Impacts how others see us in specific social settings
Reference Groups
Groups we compare ourselves to (usually groups we belong to)
- reference groups and the act of comparing ourselves to them can shape our identities
Socialization
How people and institutions from society shape our acquisition of social norms and expectations
- acts as a mechanism for identity formation
Facets of the Self
Self-Concept (self-identity) and Self Schemas
Self Verification
How we perceive ourselves
- uses self schemas: organized, specific concepts about the self
- having a good sense of humor
Self schemas affect how we behave in accordance with self verification
- the desire for others to perceive us how we perceive ourselves
Self Identity
Like self concept but with greater emphasis on social identity
Locus of Control
Where we place responsibility for events/outcomes
Internal locus of control: seeing oneself as responsible for events
External locus of control: explaining events in terms of external forces
Self Efficacy
Preception of self as capable of acting effectively in a given setting
- high self efficacy associated with internal locus of control
Defined in narrow terms
self esteem- overall self worth
Self efficacy and self esteem don’t have to go together
Locus of control, self efficacy, and self esteem contribute to
Self identity/self concept
Culture
Elements of Culture
Common practices and shared understandings that bind us together in a society
Material culture vs symbolic culture
- material- personal possessions, consumer products, buildings, roads, etc.
- symbolic- non-tangible elements of culture
Symbolic Culture
Non-tangible elements of culture
Beliefs: general cultural consensus of how the world works
Values: how the world should be, how people should act, and what should be prioritized
- help create social norms and personal values
Rituals: cultural actions that have a script; ceremonies, holidays, personal routine
Symbols: cultural shorthand for ideas; unlike beliefs and values, symbols don’t imply you buy into a value, instead are negotiable based on personal perspectives
Language: the way a culture communicates; language doesn’t equal culture
- lanugage can capture culturally specific concepts, slang
Subcultures
- Groups of people within a larger culture
- Have additional cultural practices or practices at odds with the larger culture
Countercultures
Subcultures that are in opposition to the broader culture that surrounds them
- countercultures may not choose this term for themselves
Mass Media
Radio, television, and newspapers
- small number of radio stations, newpapers and TV channels could reach large majority of public
- helps shape popular cultures (pop cultures)
- of the people (population)
Emergence of the internet has decentralized pop culture
Culture and human evolution
Culture has been a major driver of human evolution
- genetic traits that help humans use tools skillfully and participate in process of passing down that knowledge will be favored evolutionarily
- tool/technology use impacts reproductive success and evolution
Cultures change over time and interact with each other
Culture Lag vs. Culture Shock
Culture Lag: when material culture changes faster than the nonmaterial culture can “catch up”
- ex. testing introduced, took time for norms about social texting
- Can be seen within one culture or between cultures
Culture Shock: Sense of unease when immersed in a new culture
- Feeling out of place navigating new social norms in an unfamiliar environment
- immigrants, anthropologists
Migration leads to…
Assimilation and Multiculturalism
Cultural diversity
Assimilation: integration into the predominant culture
- learning major language, adopting cultural norms
- affected by residential segregation and acceptance by society
Multiculturalism: preservation of original cultures within local communities
Cultural transmission and diffusion
Transmission: elements of a culture passed down from one generation to another
- rituals, myths, values, symbols
Diffusion: cultural elements passed from one culture to another
Carbohydrates are defined by their
Common structure
- Carbon chains hydrated with hydrogen and oxygen atoms
- Cm(H2O)n
Glucose is carbohydrate fuel source in most organisms; synthesized by plants/algae via photosynthesis and consumed by animals
Monosaccharides are
Sugar monomer, building blocks of complete carbohydrates
- many can be directly absorbed into bloodstream by small intestine and broken down for energy
Either an aldose and ketose
ex. Glucose
Usually colorless, water soluble, and sweet
Classification of monosaccharides
Classified by number of carbons in their skeleton; most are D-isomers
- triose- glyceraldehyde in glycolysis
- tetrose
-
pentose- ribose (nucleic acids, RNA)
- ribose 5-phosphate key component of pentose phosphate pathway
- **hexose- glucose, fructose, galactose
**Recognize structural differences (picture)
Glucose (hexose monosaccharide)
Most abundant monosaccharide on earth, major role in metabolism and syntheiszed by plants for polysaccharide cellulose (cell wall)
- In aqueous solution, exists primarily as pyranose (ring structure)
Aldose: glucose contains aldehyde functional group
In Fischer Projection, hydroxyl on carbon 3 points opposite direction as other hydroxyl groups
Fructose (hexose monosaccharide)
Hexose with 5 membered ring
- honey, fruits, root vegetables, synthetic food additive
- high fructose corn syrup linked to obesity, diabetes
Also found in disaccharide sucrose with glucose
Galactose (hexoe monosaccharide)
Aldose that can be easily converted to glucose through metabolic pathway
Avocados, beets, honey
Milk and cheese as component of disaccharide lactose
Monosaccharides are linked by
Bonds are formed by ___ reactions
Glycosidic bonds- formed by dehydration reactions, liberating H2O molecule
- transforms hemiacetal/hemiketal group into a acetal /ketal group
What enzyme creates glycosidic bonds, what enzyme breaks them down
Glycosyltransferases create new glycosidic bonds
- glycogen synthase in the liver
Glycosidase enzyme breaks glycosidic bonds via acid-catalyzed hydrolysis reaction
- Beta-galactosidase hydrolyzes glycosidic bond of lactose to liberate glucose and galactose
**Always involve anomeric carbon of at least one sugar
Anomers
5 and 6 carbon carbohydrates have an anomeric carbon
Anomers: carbohydrate isomers that differ in their orientation of their substituents (hydroxyl group) at anomeric carbon
- ***In linear form, only carbon with double bond to oxygen
Due to carbonyl, anomeric carbon is electrophile, site of nucleophilic attack for cyclization
- Hydroxyl groups far down carbon chain serve as nucleophiles
- closer ones to anomeric carbon would cause too much steric strain
**Unlike diastereomers and enantiomers, anomers interconvert at equilibrium
Each sugar has two anomer forms
Alpha and beta monomer depending on how ring system closes during cyclization
- can completely change the properties of the sugar
Disaccharides
3 to know
Two monosaccharides joined by glycosidic bonds; physical and chemical properties depend on sugar components and where they’re linked
- crystalline, soluble in water, sweet
Sucrose- table sugar; composed of glucose and fructose
Lactose- dairy productsl galactose and glucose
- majority of worlds adults lack lactase, lactose intolerant
- all mammals express lactase in childhood for breast milk but expression turns off
- northern european and african heritages continue expression
Maltose- two glucose monomers; less sweet than sucrose
Capsule of pathogenic bacterias
Thick layer of carbohydrates that avoids detection by hosts immune system because it masks antigenic proteins on the cell surface
Polysaccharides
Use in vaccines
Long chains of carbohydrate monomers linked together
- vaccines contain inert polysaccharide capsules (mask antigenic proteins of bacteria) so immune system can recognize them
Starches
Polymers of glucose that plants use to store energy; also pack vegetables and grain with carbs
- One of the most important sources of dietary carbohydrates
- potatoes, rice, wheat
Made up of 30% amylose and 70% Amylopectin
Glycogen is used for
Where is it stored in animals?
In cytoplasm, glycogen chains are attached to ____
Storage of flucose in animals, fungi, and bacteria
Stored in the liver and skeletal muscle
- Liver synthesizes glycogen from glucose when energy is abundant, breaks in down if not
- Skeletal muscle tends to store it uses it to power muscles during exercise
In cytoplasm, glycogen chains are attached to core protein glycogenin
Cellulose (polysaccharide)
Why can’t humans break it down?
Dietary fibers
Polysaccharide of glucose monomers responsible for rigidity of cell walls
- linked together via b-1,4 glycosidic bonds rather than alpha anomer in starch and glycogen
- Humans lack enzyme that can break this bond
However, important component of dietary fiber which play role in nutrient absorption and gastric motility, elminated as waste
Chitin (polysaccharide)
**Peptidoglycan (polysaccharide)
Structural support for shells or exoskeletons of insects, crustaceans, and mollusks as well as fungi cell walls
Makes up bacterial cell wall
Cyclization of linear monosaccharides forms
What happens to anomeric carbon when linear monosaccharide cyclizes
Either furanose: 5 carbon rings or pyranose: 6 carbon rings
Anomeric carbon functional group changes from aldehyde or ketone to hemiacetal or hemiketal
- alcohol attacks carbonyl carbon
Depending on which side the OH group attacks the anomeric carbon, either form alpha anomer or beta anomer
alpha anomer vs. beta anomer (monosaccharides)
Why does it matter?
Mutarotation: Alpha and beta anomers can rapidly interconvert
Alpha anomer: hydroxyl group points down
Beta anomer: hydroxyl group points up
Type of anomer formed affects the type of glycosidic bond that forms between sugars
Glycosidic Bond Hydrolysis Mechanism
Reverse of dehydration reaction in bond formation
- OR group attached to both sugars is protonated by an acid, forming leaving group
- Molecule of water attacks anomeric carbon in glycosidic bond kicking off protonated OR group
- Newly added water molecule deprotonated to form OH group
Maillard Reaction (redox with carbs)
**Reducing sugars
Gives food its distinctive brown color when burned; occurs between 140 and 160 deg C
- Amino acids in foods react with certain carbohydrates
- happens faster under basic conditions, amino groups deprotonated
- At very high temps, carcinogen acrylamide can form if the food is charged
Reducing sugars act as reducing agents with amino acids
- All monosaccharides
- any sugar with free aldehyde and non-aldose sugars that can be converted to an aldose (fructose)
- due to keto-enol tautamerism
- disaccharides and polysaccharides with free anomeric carbons
Cu2+, Ag+, Fe3+ detect reducing sugar presence in reactions
Testing for reducing sugars is critical for:
Tollen’s test
Benedicts test
Diagnosis of diabetes; diabetics have abnormally high blood glucose from not producing enough insulin or cells not responding to it
- excess glucose ends up in urine
Fehlings test was also used for detection
Silver ions used to oxidize an aldose (reducing sugar) which produces solid silver
Similar reaction with Cu2+ instead; begins with bright blue color and turns into red
Stereoisomers
Chiral center
Enantiomer definiton
Isomers that differ in the spatial arrangment of their atoms around a stereocenter
Chiral center is a stereocenter bound to 4 different substituents
- enantiomers: a molecule with a single chiral center is asymmetrical, non-suuperimposable on its mirror image
** Number of possible stereoisomers doubles with each stereocenter
Superimposable definiton
Ability of an object to be placed over another object
Achiral molecules or meso compounds (multiple chiral centers that form a plane of symmetry
Carbohydrates tend to have ____ chiral carbons
Chirality of each carbon is important because
1 to 5
Chirality of each carbon is important because it changes biological function and glycosidic bonds capable of forming
Diasteroemers
Differ at one or more stereocenter/chiral center, but not all of them (then they’d be enantiomers)
d/l (+/-) system for carbohydrate stereochemistry
(rotation of plane-polarized light)
Classifies compounds based on how they rotate plane-polarized light in a device called polarimeter (has to be determined experimentally)
- Chiral molecule either rotates light CW or CCL
- different from uppercase D/L
d-compound(+) rotates light clockwise
l-compound(-) rotates light CCW
R/S system
Go-to system for describing compounds with 1 or two stereocenters
R = clockwise
S = CCW
Priority Rules:
- Identify stereocenters
- Assign priority of groups by higher atomic number, then mass, then # of bonds
- Lowest priority group points away (dashed line)
- Assign R/S designation
One non-superimposable mirror image will be R and the other will be S
D/L system
Based on the fischer projection of glyceraldehyde (3-carbon aldose) which has one stereocenter
- enantiomers have one with hydroxyl group pointing right, one with hydroxyl group pointing left
- Hydroxyl group pointing right is D-isomer
** For compounds with more than one stereocenter, look at OH group on the highest numbered Carbon
- If pointing to the right, D
- if left, L
**Only D-isomers in biological processes
Do enantiomers of carbohydrates (and any molecule) interconvert at equilibrium?
No, only D sugars are used in biological process
Enantiomers
Stereoisomers that are non-superimposable mirror images
- configuration is opposite at each stereocenter
Epimers
Type of diastereomer that differ at ONLY one stereocenter
1 epimer for every chiral center
D-Glucose different stereoisomers
16 stereoisomers
- 2 enantiomers
- 14 diastereomers
- 4 epimers
Cyclic Carbohydrate conformations
Which are most stable for 6 carbon rings (pyranoses)?
For furanoses (5 member rings)
3D structures that can be rearranged without breaking bonds
Pyranoses: Most stable are chair and boat, whichever form is less directly hindered predominates
Furanoses: Most stable are envelope
Immune System 2 primary functions
- Prevent foreign pathogens from entering the body
* through physical barriers (skin), antimicrobial enzymes, and immune cells - Destroy any pathogen that manages to slip through
- as well as damaged or infected host cells
- because of its ability to attack host cells, one of the most powerful organ systems; dysfunction can damage/destroy healthy tissue
How does immune system distinguish pathogens from host cells?
Antibodies: Y shaped protein structures produced by B cells of the immune system
- track down and bind to pathogens
Antibodies structure (3 regions)
3 regions:
1. Constant- same across all antibodies
2. Variable- differs in order to detect different types of antigens (foreign molecules)
3. Hypervariable- also differs; contains antigen binding site that recognizes and binds a singular antigen
- one to one specificity of antibody to antigen
Antibody-antigen binding
Antigen binding site: undergoes extensive genetic recombination in B cells to create diversity to detect infinite range of antigens
- located in antibody hypervariable zone
Antigen-antibody binding marks the pathogen, makes it harder to infect host cells, makes pathogen easier to find and destroy
Antibodies distinguish “self” proteins from “non-self” proteins
Antigen
Epitope
Any recognizable component of a pathogen
Epitope: site where an antigen is recognized by an antibody
- specificity helps prevent immune system from targeting healthy tissues
Immune Cell Types
5 types
Abundance and function
Referred to as white blood cells or leukocytes
- Produced in bone marrow and nucleated (UNLIKE more abundant red blood cells)
Neutrophils: most abundant leukocyte (60%); track down pathogens like bacteria and destroy by phagoctyosis (classified as phagocytes)
Lymphocytes: 30% of white blood cells; T cells and B cells (B cells produce antibodies), as well as natural killer cells which target and destroy infected host cells
Monocytes: 5% of leukocytes; largest by size, **differentiate into macrophages and dendritic cells
-
macrophages: phagocyte; dispose of cellular debris and non-cellular foreign material
- non-specific phagocytes that engulf and digest almost anything, including cellular debris, tumor cells, foreign substances, and microbes.
- dendritic cells:
Eosiniphils: target parasistic infections
Basophils and mast cells: inflammatory cells, release histamine as part of allergic response
Neutrophils
Lymphoctyes
Lymphocyte maturation
30% of white blood cells; T cells and B cells (B cells produce antibodies), as well as natural killer cells which target and destroy infected host cells
-
ADAPTIVE immune cells
- antigen specific- each T or B cell will only target a specific group of structurally similar antigens
During maturation, undergo genetic recombination creating diverse set of cells
Monocytes
Eosinophils
Eosinophils are a type of disease-fighting white blood cell. This condition most often indicates a parasitic infection, an allergic reaction or cancer
Basophils and mast cells
Inflammatory cells, release histamine as part of allergic response
Granulocytes
Immune cells that contain cytoplasmic granules(small particles, usually for storage) rich in proteolytic enzymes
- Neutrophils- neutral color
- Eosinophils- acid-loving granules, stain red with acidic dyes
- Basophils and mast cells- base loving dyes, stain blue with base loving dyes
Bone Marrow
Hematopoiesis
Viscous tissue present in the interior of most of the larger bones in the body
Hematopoiesis: production of red and white blood cells in bone marrow
- hematopoietic stem cells can differentiate into T cells, B cells, neutrophils or other white blood cells
- also produces red blood cells and megakaryocytes (precursor to platelets)
Diseases that attack bone marrow
Treatment involves
Leukemia and other cancers of the blood, comprimises the immune system because of bone marrows function
Treatment involves radiation followed by infusion of new hematopoietic stem cells (bone marrow transplant)
- shows promise in treatment of HIV and others as well
- both known cases of curing HIV were transplans of bone marrow from healthy donor who had HIV immunity
Spleen immune system function
Parts of spleen known as white pulp are rich in lymphocytes and important for B cell activation
Thymus
Small organ in the chest where T cells mature (education)
Lymphatic system anatomy
What is lymph
Lymph nodes
System of vessels that helps transport fluid and immune cells throughout the body
- As blood flows through capillary vessels, some of this fluid leads into the tissues and collects in interstitial space
Interstitial fluid drains into lymphatic vessels in the form of lymph:
-
lymph: colorless, lipid-rich fluid that flows through lymphatic system
- eventually is returned to venous circulation
lymph nodes: pockets of lymphatic tissue that house high concentrations of T and B cells; swell during periods of infection, hundreds located throughout body
Lymphatic system also connects thymus and spleen
Lymphatic system four main functions:
What type of biomolecule is transported?
- Maintaining fluid balance
- Collecting and returning interstitial fluid to circulation
- Transporting cells and biomolecules within lymph (LIPIDS)
- Producing lymphocytes
Autoimmunity
Occurs when…
examples of autoimmune disorders
Any action of the immune system directed toward healthy host tissues
- Antigen-antibody system to prevent wrongful attack
Occurs when immune response is too strong
ex. Rheumatoid arthritis- autoimmune disorder where immune system attacks joints causing systemic joint pain
ex. Allergic response- immune system attacks harmless foreign body; can induce anaphylactic shock
* might be caused by lack of exposure to antigens
Histamine
chemicals your immune system makes. Histamines act like bouncers at a club. They help your body get rid of something that’s bothering you – in this case, an allergy trigger, or “allergen.” Histamines start the process that hustles those allergens out of your body or off your skin.
- Once released from its granules, histamine produces many varied effects within the body, including the contraction of smooth muscle tissues of the lungs, uterus, and stomach; the dilation of blood vessels, which increases permeability and lowers blood pressure; the stimulation of gastric acid secretion in the stomach; and the acceleration of heart rate. Histamine also serves as a neurotransmitter, carrying chemical messages between nerve cells.
Also in many stinging animals venom
Two divisions of the immune system
Innate immune system (army) and adaptive immune system (spy)
- work separately and in tandem, like when helper CD4 T cells recruit neutrophils, macrophages and other innate immune cells
Innate immune system (army)
What is used for protection against pathogens entering the body?
Broad, non-specific protection against microbes to prevent infections; acts very quickly!
- Prevent pathogens from entering body and bloodstream
- Skin (epidermis)
- Mouth
- Other major orifices: nasal and ear, rectum, urethra rectum vagina
-
Cellular response
- inflammation
Adaptive immune system (spy)
Specific targets its weaponized against; LYMPHOCYTES (T and B cells)
- antibodies
Remembers pathogens!
Epidermis immune functions
skin (epidermis)- cells are packed very tightly, making it difficult for foreign bodies to slip through
Sweat and shedding of skin naturally clears potential infectious pathogens
Mouth
Pathogens that survive oral cavity?
Saliva contains antimicrobial lysosyme which breaks down bacterial cell walls
- pathogens that survive oral cavity are likely to be damaged/destroyed by acidic environment of stomach
If bacteria makes it past the stomach
It has a chance of being abosrbed in intestinal lining or will pass through and be excreted
- even if bacteria attempt to colonize the intestines, growth is limited my healthy gut flora already present
What blocks entry of pathogens into ear
Tympanic membrane
How does nose, rectum, urethra and vagina block entry of pathogens?
Mucous lined membranes
Cellular response to an immune infection
- Most abundant leukocyte, Neutrophil is first on the scene of an infection
- follows a chemical trail of chemotaxic signals where it begins phagocytizing invasive bacteria
- Macrophages also phagocytize cellular debris
Inflammation
4 signs of inflammation
Necessary part of protecting and healing responses to injury and infection
- immune response to presence of foreign pathogens
1. Calor- heat
2. Dolor- pain
3. Rubor- redness
4. Tumor- swelling
Basic method of inflammation
Vasodilation of blood vessels at sight of injury or infection –> increased blood flow
- allows immune cells to travel quickly
Pathways that upregulate or downregulate inflammatory response are partially regulated by
Cytokines
Interferons
Immune response for viruses
T Cells
Two subclasses
Lymphocyte (adaptive immune system) that is matured in the Thymus (“T” cell)
- produced during hematopoiesis in bone marrow
- ANTIGEN PRESENTING CELLS:
Divided into two classes depending on response to Major Histocompatibility Complex (MHC) on the surface of other cells
- Most cells in body express MHC-1 receptors
- when cell is damaged, displays antigen on MH1 receptor which is recognized by CD8 T cells who lyses it
-
MHC-2 receptors are only found on immune cells like macrophages and dendritic cells who phagocytize antigens and present antigens to T cells
- antigen at MHC2 receptor interacts with helper CD4 T cells, which secretes cytokines that activate/recruit other innate immune cells
T-cell maturation
Faulty maturation can lead to
T-Cells must survive two phases which elimnate under or overreactive ones = Positive Negative Selection
- T-cells that fail to respond to general antigens are eliminated by positive selection
- T-cells that attack self proteins and are too reactive are elminated by negative selection
Rheumatoid arthritis
Crohns Disease
Lupus
Multiple sclerosis
When a normal cell is infected with a virus…
When antigen presenting cell engulfs a microbe and presents its antigen on MHC 2 receptors…
After serving their duty as effector T cells, both CD4 and CD8 T cells can differentiate into…
It expresses viral antigens on MH1 receptors so that CD8 killer T cells can destroy them and curtail infection
Activate helper CD4 cells to mount appropriate response
Memory T cells that remember antigen they were exposed to and mount a faster response next time
Memory T cells
How we develop immunity. Come from used T cells that differentiate after doing their job
Used to create vaccines
B Cells - adaptive immune system humoral response
B cells are produced in the bone marrow and their primary function is to secrete antibodies, which bind to antigens and mark them for destruction
- after production in bone marrow, migrate to secondary lymphatic organs like lymph nodes and the spleen, where they can interact directly with antigen presenting cells
If B Cell encounters antigen it has a receptor for, it either matures into a plasma B cell which produces antibodies or a memory B cell
Cell mediated response
Humoral response
T cells
B cells, antibodies
Cytoskeleton function
- Shape and structure
- Motion
- Cell division
- Organelle and biomolecule transport
Cytoskeleton structures (3 protein polymers)
1. Microfilaments
2. Intermediate filaments
3. Microtubules
Cell can add or remove protein subunits for each type of polymer to control filaments length or thickness
Microfilaments are composed of ____ proteins
Microfilament function
Actin
- Essential to cellular motility and maintaining cells structure (more rigid)
Also contribute to cytokinesis in cell division
And interact with myosin for muscle contraction
individual Actin monomers are called
Monomers are strung together to form
G-actin because of their globular shape
F-actin polymer (filamentous actin)
- Typically, two strands of F-actin stuck together to form microfilament
Treadmilling (cytoskeleton)
Microfilaments are directional;
- ATP bound actin monomer latches on to + end of elongating filament, which is hydrolyzed into ADP
- Therefore + end is ATP heavy and - end is ADP heavy and shrinks
- Caps can be placed at either end to stop this
When both happen at the same time, it is treadmilling and is reason that cytoskeleton has dynamic rapid growth and disassembly
_**_This also occurs for microtubules
Intermediate filaments are
Where are they found and what do they do?
Made up of different protein monomers; more stable and don’t bind nucleotides like other two cytoskeleton fibers
- alpha helical structure makes them more flexible
Typically found in cytoplasm providing structural support
- also adhere to other cells and position organelles
ex. Keratin (hair and nails)
Microtubules function
Where do they function
Structural support for cilia and eukaryotic flagella
Chromosome separation during mitosis/meiosis
Intracellular transport
Function at Microtubule Organizing Centers (MTOCs): basal bodies in cilia and flagella and centrosomes
Basic structure of microtubule
How does polymerization occur?
Monomer unit is actually a Tubulin dimer, composed of alpha tubulin and beta tubulin
Like microfilaments, have nucelotide binding sites, but instead are for GTP and GDP
- Polymerization occurs when theres a high enough concentration of dimers to exceed threshold
- depolymerization below this threshold
3 types of motor proteins
**Attach to cytoskeletal filaments
- Kinesins
- Dyneins
3. Myosins
Motor protein functions
Transport, motility, muscle contraction
Kinesins
anterograde transport
Made up of 4 subunits
ATP-ases: consumes energy from ATP hydrolysis to power movement
- Travel along microtubules to transport cellular cargo
- Anterograde transport: Move towards positive end of microtubule (towards periphery of the cell, away from center of cell)
4 subunits:
- 2 are heavy chains, function like legs
- Head groups = feet
- Stalks between head groups and heavy chains
- 2 heavy chains bind to two light chains which attach to cargo
How do kinesins move
ATP binds to a head group which locks it to microtubule and triggers conformational change, swinging second head group forward (toward positive + end)
- Then ATP is hydrolyzed to ADP causing it to detach
Dyneins
Their transport is called
Two types of Dyneins
Like Kinesins but move to (-) negative end of microtubules, towards cell center, also an ATP-ase
- Retrograde transport
1. Axonemal- only in cells with cilia or flagella, generate motion for these structures to move
2. Cytoplasmic- transport cargo, organelle and vesicle components
Myosins
3 domains
Also an ATP-ase
- used for muscle contraction
Composed of head, neck, and tail domains
- Head domain binds actin and hydrolyzes ATP to power myosins movement
- Tail binds to cargo and other myosin
Cell Adhesion Molecules (CAM) proteins
3 types of CAMS
Proteins on cell surface that glue cells together
- Associate with cytoskeletal elements or
- Anchor to eachother and extracellular matrix (network of proteins, sugars, other biomolecules
Cadherins, selectins, and integrins
Selectins (CAM protein) function
Found on…
Function: mediate inflammatory response
Found on immune cells, platelets, and endothelial cells lining blood vessels
- They bind to leukocytes moving through bloodstream, slowing them down to allow them to work at infected area
heterophilic- two pieces binding are different
Cadherins
Transmembrane proteins that bind to other cadherins for cell growth and development, cell adhesion
- contain calcium ions, dependent on them for adhesion
Homophilic
Integrins
Adheres to extracellular matrix and is used for cell signaling, binding ligands and cations (receptors of other cells)
- located on cell membrane
INTEGRATES cell adhesion with cell signaling
Cell junction types
Anchoring junctions
Gap junctions
Tight junctions
Anchoring junctions
Connect cytoskeletons to each other or to extracellular matrix
- help stabilize cells and tissues
Adherins junctions- cadherin proteins interact with actin filaments
Desmosomes- cadherin to intermediate filaments; located where withstanding force is necessary- heart, bladder, epithelial
Gap junctions
Created by connexin proteins, link cytosol of neighboring cells
- facilitates cell to cell communication
Allows passage of amino acids, Ca, cAMP
Found in most tissues but most relevant in tissues that require electric/chemical signaling
- ex. cardiac muscles (cells can contract at same time)
Tight junctions
Found in epithelial cells, link cells very closely and doesn’t allow passage of macromolecules, only water and some ions
- occludin and claudin proteins
ex. Blood brain barrier
Antibodies are
Chain components
Y shaped immunoglobulins
- glycoproteins made by B cells
- Antibodies help neutralize foreign invaders like viruses and bacteria as well as threatening cells in the body
Two heavy chains(longer), two light chains connected by disulfide bonds
- constant, variable, hypervariable
Can be secreted as dimers, tetramers, etc linked ny the STEM of their Y shape
Antibody classes are known as
5 classes
Isotypes- different functions in immune response
- IgA- blocks pathogen attachment in intestine, respiratory tract, saliva, genital tract
- IgD- antigen receptors on surface of naive B cells
- IgE- allergic and antiparasitic immunity (stimulates histamine)
- IgM- early response
-
IgG- most common, in blood and extracellular fluid
- eliminates bacteria and viruses
Class Switching
B cells can change production of one isotype to another, repurposing their antibodies
- constant region changes but hypervariable (antigen binding site) stays the same
ELISA
Utilizes carefully picked antibodies to detect a substance of interest
Excretory system key structures
Kidneys, Ureters, Urethra, urinary bladder
Kidney and key components
Functional unit of the kidney
Bean shaped organs near back of abdominal cavity
- Renal arteries supply each kidney with blood which drains by renal veins
Each kidney is protected by tough fibrous layer called renal capsule
- inside, kidney itself consists of:
- Renal cortex: outer region
- Renal medulla: inner region
The functional unit of the kidney is the nephron, which spans both regions
- nephron consists of renal copuscle and renal tubule
Nephron
Filtrate? Path of Urine through kidneys
- The functional unit of the kidney is the nephron, which spans both regions
-
nephron consists of:
- renal copuscle: flood is filtered into nephron, located in renal cortex (outer region of kidney)
- renal tubule: filtrate travels through renal tubule until reaching collecting duct, then drains as urine
-
nephron consists of:
Filtrate: water and solutes which eventually become urine
- Once urine drains from collecting duct, passes through medullary pyramids into minor calyces and then into major calyces
- urine then drains from renal pelvis which becomes the URETER
Each kidney contains about 1 million nephrons
Ureters, Urinary Bladder, Urethra
Two tubes, one from each kidney, which brings urine from kidneys to urinary bladder that sits on pelvic floor
- urinary bladder contracts to excrete urine through the urethra
Release of urine through the urethra is controlled by
Internal and external urethral sphinctor muscles
- internal urethral sphincter controlled by smooth muscle and the autonomic NS
External urethral sphincter is made up of skeletal muscle and is controlled consciously
Renal corpuscle consists of
Glomerularis, a tight bundle of capillaries
- blood enters them from afferent arterioles BUT also exits from an efferent arteriole instead of a vein
and Bowmans capsule which wraps around the glomerularis
Filtration in the nephron
(in corpuscle) Blood traveling through glomerularis is subject to hydrostatic pressure which causes some water and small particles to filter into Bowmans capsule = filtrate
- filtrate consists of water, salts, vitamins, glucose and amino acids
Renal tubule (in the renal medulla) consists of
Functions (3)
Renal tubule has to adjust volume of filtrate, reabsorb valuable nutrients, expels waste
Proximal convoluted tubule- reabsorbs valuable nutrients (glucose, free aminos, water soluble vitamins, sodium)
- picked up by blood capillaries
Loop of Henle- has a descending and ascending limb; allows for retention of large amounts of water and solutes
- reduces volume of urine without reducing concentration
Distal convulated tubule
Most important function of nephron
Reabsorption of all glucose
- glucose concentration in blood is a sign of disease like diabetes; too much blood sugar to be reabsorbed
Countercurrent Multiplier System
Loop of Henle. descending and ascending limb functions
Concentration of sodium increases as you go deeper into renal medulla
Loop of Henle- has a descending and ascending limb; allows for retention of large amounts of water and solutes
- reduces volume of urine without reducing concentration
Descending limb: permeable to only water and not ions; as it goes into higher sodium concentration, water drains out of the loop of henle reducing its volume
- water is picked up by vasa recta blood vessels and returned to circulation
Ascending limb: permeable to ions but not water; Na and K ions flow out and are picked up by vasa recta
- at bottom of ascending limb its thin and allows for passive transport
- at the top, its thicker and needs active transport
Blood in vasa recta runs opposite direction as loop of henle
Excretory system regulates what 4 components of homeostasis
- Blood pressure
- Osmoregulation
- Acid base balance
- Nitrogenous waste
Excretory system regulation of blood pressure
Blood volume, pressure and osmolarity are regulated by:
Blood pressure regulated by cross sectional area of vessels, vasodilation, and also by fluid volume which can vary dramatically
- when someone is dehydrated, blood volume and pressure is low
Aldosterone: increases sodium reabsorption and therefore water reabsorption, increasing blood pressure
Angiotensin II: increases BP and stimulates aldosterone release
Antidiuretic Hormone: increases blood volume and pressure
**Atrial natriuretic peptide: decreases blood volume and pressure
Distal Convoluted Tubule and Collecting duct ( in Nephron) are acted upon by
DCT and collecting duct are acted upon by hormones:
- Aldosterone- stimulate sodium reabsorption
- Antidiuretic hormone (Vasopressin)- promotes water reabsorption
DCT: sodium, Ca, Cl, H ions reabsorbed and K, H can be secreted
- aldosterone promotes sodium and therefore water reabsorption here
- can also be acted on parathyroid hormone, which stimulates calcium reabsorption
Collecting duct: ADH acts to promote water reabsorption
Aldosterone
Regulated by? Mechanism?
Increases sodium reabsorption, promoting water reabsorption, increases plasma volume and pressure
Regulated by reinin-angiotensin-aldosterone axis
- juxtaglomerular cells stimulated by low blood pressure, low sodium, or sympathetic NS input to release enzyme called renin in kidneys
- Renin acts on angiotensinogen to make angiotensin I
-
ACE enzyme converts angiotensin I to angiotensin II, which triggers release of aldosterone from adrenal cortex
- also stimulates vasoconstriction
Antidiuretic Hormone (ADH) (Vasopressin)
Promotes water retention by increasing water reabsorption in collecting duct of kidneys
- promotion of aquaporins in collecting duct cells
Vasoconstriction, increases blood pressure and volume
HOWEVER, reduces osmolarity of blood (no effect on solute)
Atrial Natriuretic Peptide (ANP)
Hormone secreted by the heart to decrease blood pressure
- sodium retention in the nephron
Excretory system regulates blood pH
pH must be kept between 7.35 and 7.45
Blood pH is usually decreased by lactic acid and CO2 levels (bicarbonate buffer)
** excreting more protons in urine can also decrease aciditiy, inhibiting this can do the opposite
- done by Sodium-Proton exchangers
Removal of soluble nitrogenous waste
Urea is removed via excretory system
- urea is carbonyl containing 2 amine groups
- ammonia is a biproduct
- in excessive levels, becomes toxic to the body
Liver converts ammonia to urea which is secreted through nephron for excretion
Boiling does not require that Pvap > Patm; it only requires that Pvap = Patm.
Why is ice less dense than water
For most substances, the liquid becomes more dense as the average kinetic energy (temperature) decreases, and the solid is more dense than the liquid due to close-packing solid-state structures, resulting in the formation of the solid at the bottom of the liquid. However, as stated in the question, solid water (ice) is significantly less dense than the liquid form at 0°C (the melting/freezing point). Remember, the water molecule is bent (shown below), with a bond angle of approximately 104.5°. This, combined with the degree of hydrogen bonding that can occur between water molecules, yields a solid crystalline structure with relatively large amounts of empty space. As a result, solid water is less dense than its liquid form.
The MCAT will expect you to be familiar with N2 as a very inert gas. It makes up approximately 80% of the air you breathe, yet has no significant chemical reactions with your lungs – or with anything other than nitrogen-fixing plants. This information implies that nitrogen is very inert (unreactive). As such, it would serve as a good artificial atmosphere when working with reagents that might react with oxygen or other gases.
Ka =
Keq
Amines are
Derivatives of ammonia (NH3)
- when uncharged has a lone pair of electrons
WEAK BASES
Naming amines
When highest priority functional group, name ends with amine
- when anoother higher priority functional group, denoted by -amino
Primary amines have one alkyl group, secondary have two, and tertiary have 3
Nitrogenous bases are (what functional group)
Cyclic amines, some with two rings
Primary or tertiary amines have a higher boiling point?
Primary because more hydrogen bonding
- however H-bonding in amines isn’t as strong as alcohols or carboxylic acids due to electronegativity
Alkyl vs. Aryl amines
Aryl amines have aromatic substituent
- less basic than alkyl amines due to lone pair resonance
Imines contain
Carbon nitrogen double bond
Enamines contain both
Hybrid of two functional groups: alkenes and amines
ENamine
Imines and enamines are
Tautomers, can easily interconvert under acidic or basic conditions
Amides
Carboxylic acid derivatives, Nitrogen bound to carbonyl group
Extremely weak bases due to carbonyl withdrawing; considered neutral (amino acids)
Garlic, skunk spray, and rotten eggs have what in common
Created by thiols
Thiols
Boiling points compared to alcohols? Acidity?
Compounds with S-H group
- polar but capable of only weak hydrogen bonding
- much lower BP than alcohol
However, more ACIDIC than alcohols (still weak acids)
Thioethers
Sulfur and two R groups; tend to act as bases
- methionine
- biotin
Thioesters
Biologically important thioesters
Carboxylic acid + thiol
- derivatives of Coenzyme A = acetyl CoA (key intermediate in aerobic respiration and fat metabolism)
Disulfides
Two bonded sulfur atoms which are also bonded to an alkyl group RSSR
- Important aspect of tertiary structure of proteins
Like peroxides, which have oxygen instead of sulfur (ROOR)
stabilize the tertiary and/or quaternary structures of proteins
Role of lipids
Types of lipids
Energy storage, structural support to cell membranes, chemical messengers
- Fatty acids and derivatives
- Cholesterol and derivatives
- Eicosanoids
- Terpenes and terpenoids
Fatty acid structure
Fatty acid derivatives
Fatty acids are commonly stored as
Lipid with acidic functional group (carboxylic acid attached to linear hydrocarbon chain)
- Fatty acid derivatives:
- triglycerides
- phospholipids
- sphingolipids
Fatty acids are commonly stored as TRIGLYCERIDES
Head of a fatty acid
Tail
Carboxylic acid
Hydrocarbon chain
Triglyceride structure (fatty acid derivative)
Triglycerides are stored in ____ for what use?
3 fatty acid chains, esters, glycerol
- typically what we consider fats in our food
Stored in adipocytes as energy reserves
Saponification
What about structure of soap makes it function?
Esters are carboxylic acid derivatives that can be split into components via nucleophilic reaction
- When this happens to triglycerides, its called saponification (soap making)
Done by mixing fat with a strong base, cleaves the triglycerides making glycerol and fatty acid salt
- Cation and carboxylate anion and fatty acid tail is excellent for solubilizing hydrophobic dirt/grime
Sphingolipids (fatty acid derivative)
Sphingomyelin
Fatty acid residue bonded to sphingosine amine group
Tendency to cluster in lipid rafts within plasma membrane; biosignaling
Waxes (fatty acid derivative)
Composed of a mixture of lipids
- produced by plants and animals
- solid but malleable at room temp
Cholesterol
What is cholesterol a precursor for?
Component of cell membranes (maintains fluidity), orchestrates secondary sex characteristics through steroid hormones, and regulating calcium metabolism
4 FUSED RINGS
- precursor for steroid hormones
- aldosterone
- estradiol
- vitamin D- regulating calcium metabolism
Eicosanoids (lipids)
2 subclasses:
Signaling lipids –> allergic response, pain perception, blood pressure regulation
-
Prostaglandins: synthesized from arachidonic acid
- mediate pain and inflammatory responses
- Thromboxanes: found in platelets, facilitate blood clotting
Terpenes and terpanoids
Terpenes = class of hydrocarbons made from isoprene (5 carbon unit w/ 2 double bonds)
- terpanoid: terpene with additional functional groups
Vitamin A (retinol) is a terpanoid
Lipid soluble vitamins
A, D, E, K
Vitamin A = terpanoid
Vitamin D = cholesterol derivative
Unsaturated vs. Saturated fats
Saturated fatty acids have no double bonds
- saturated with hydrogen bonds
Unsaturated have at least one double bond
Fatty acid naming
Numbering chain starts with carbonyl carbon, any double bonds are named by the lower number
- Z = cis
- E = trans
Lipid Numbering
Only gives total number of carbons and double bonds
ex. 16:1 Fatty Acid
Omega Fatty Acid Naming
Numbers carbon chain from hydrocarbon chain first
- opposite of IUPAC
Delta Fatty Acid Notation
Used to identify position of double bounds in fatty acid chain
- same as IUPAC; starts counting at carbonyl
Unsaturated Fatty Acids
Trans fatty acids
Usually have a cis bend that creates a kink in the hydrocarbon chain, causing loose packing
- LOW melting and boiling points
Sometimes liquid at room temp
Trans fatty acids: contain trans double bonds, more stackable than cis
- more likely to be solid at room temp
- Additive to food, greatly elevate risk of heart disease
- *increases LDL:HDL ratio
SATURATED fatty acids
Tight packing, high melting point, solid at room temp
How do lipids travel through bloodstream?
Lipoproteins: vehicles for lipid transport
- lipids absorbed by brush border in small intestine
- Packaged into chylomicrons- lipoproteins composed of triglycerides
* also contain apolipoproteins: amphipathic proteins that can bund lipids while interactring with polar solvents
After chylomicrons are formed with triglycerides
They are released into lacteals, small vessels that drain into lymphatic system
- from here, deliver fatty acids to adipose tissue, skeletal muscle, and cardiac muscle
After delivering lipid cargo, chylomicrons are repurposed in the liver
Liver produces important lipoproteins
Identified based on density (LEAST dense has HIGHEST ratio of lipid to protein):
VLDL (very low density lipoproteins): very rich in triglycerides, delivers them to body tissues
VLDL (very low density lipoproteins):
very rich in triglycerides, delivers them to body tissues
- triglycerides come from fatty acids synthesized in the liver and chylomicron leftovers
Circulates bloodstream releasing TGC’s, is converted to LDL
IDL (intermediate density lipoproteins)
VLDL is converted to IDL in the bloodstream after dropping off TGC’s
- some IDL particles return to liver, others become converted to LDL
LDL (low density lipoproteins) main function:
High LDL means
- converted from IDL after dropping off more TGC in bloodstream
Contains more cholesterol than triglycerides
- **main function is to deliver cholesterol
High LDL = increased cardiovascular risk, contributes to formation of atherosclerotic plaques
HDL (high density lipoprotein)
High HDL means
Picks up stray cholesterol and other lipids and brings them back to the liver
- Cholesterol transporter
High HDL = good cardiovascular health, decreased risk of atherosclerosis, unhealthy narrowing of blood vessels from plaque buildup
How are fats mobilized from adipocytes/adipose tissue to be used for energy metabolism?
Hormones epinephrine and glucagon tell adipocytes to release fatty acids
- active the enzyme hormone sensitive lypase, which hydrolyzes triglycerides
Free fatty acids released into bloodstream and are transported to target tissues by blood protein albumin
Breaking down fats for energy is two processes:
Lipolysis and beta-oxidation
Lipolysis
Fatty acid molecules are mobilized from storage and moved to bloodstream to be picked up by cells that need energy
- Triglycerides mobilized from adipose tissue made up of adipocytes
- hydrolyzed into glycerol and fatty acid chain components
Carried by albumin
Beta-oxidation overview function
Free fatty acids in mitochondria are broken down into
Fatty acids are oxidized to produce intermediate molecules which produce energy
- ** After lipolysis, free fatty acids enter cells from bloodstream and are shipped into mitochondria
Broken into Acetyl CoA’s (2 carbon molecule)(much more than made by pyruvate decarboxylation)
- can be fed into CAC to generate ATP via aerobic respiration
How do free fatty acids enter mitochondria membrane for beta-oxidation?
To enter matrix?
Moved from cytosol into mitochondrial matrix by adding a molecule of Coenzyme A, creating Acyl CoA
- fatty acid can’t enter mito without it
Short fatty acid chains can diffuse into matrix, longer chains have to use carnitine shuttle (reference picture)
- serves as a control point for regulating fat metabolism
- only active when cell needs fat for energy
Steps of Beta-oxidation of an even numbered saturated fatty acid
- Goal is to get 2-carbon acetyl CoA; each round liberates 2 carbons from polar head of fatty acid
- Each round takes place in 4 steps:
- Oxidation
- Hydration
- Oxidation
- Thiolysis (cleavage)
Step 1: Beta Oxidation: Oxidation
Acyl CoA Dehydrogenase creates double bond between beta and alpha carbons adjacent the carbonyl
Produces 1 FADH2 and trans-∆2-enoyl-CoA
Step 2 Beta Oxidation: Hydration
Product of 1st oxidation has addition of hydroxyl group to beta carbon which used to be part of double bond created in first step
- double carbon bond is used to add oxygen
Step 3 beta oxidation: Oxidation
The hydoxyl added in step 2 is oxidized further into a carbonyl group
- creates one NADH from NAD+
Creates Keto
Step 4 Beta oxidation: Thiolysis (cleavage)
FRESH molecule of COENZYME A cleaves the fatty acid into molecule of Acetyl CoA and new fatty acid that is two carbons shorter
Beta oxidation of an unsaturated fatty acid with an odd numbered double bond
Beta-oxidation proceeds normally until it meets double bond
-
Odd numbered double bonds dealt with by enzyme enoyl-CoA isomerase
- moves double bond to an even number
- fatty acid becomes another trans-∆2-enoyl-CoA and can proceed with second step of beta O (hydration)
Beta oxidation of unsaturated fatty acid with an even numbered double bond
Even numbered double bond:
- Beta oxidation proceeds until double bond is on carbon 4, then acyl-CoA dehydrogenase creates another double bond in between it and the carbonyl
- Enzyme 2,4-dienoyl-CoA reductase couples oxidation step with reduction of NADPH to NADP+ that produces a double bond at position 3
- Enoyl-CoA isomerase moves double bond between alpha and beta carbons
Beta oxidation can proceed normally
Beta oxidation of fatty acid with ODD number of carbons on chain
Process halts with 5 carbons remaining: creates 1 acteyl CoA and 1 propionyl CoA
Propionyl CoA can be turned into Succinyl CoA and enter citric acid cycle
Each round of beta oxidation produces
How much ATP?
Each round produces 1 FADH2, 1 NADH, 1 acetyl CoA (final step produces 2 acetyl CoA or 1 and 1 propionyl CoA)
About 14 ATP per 1 round (multiple rounds for a fatty acid chains)
- 7n ATP per “n” carbon in chain
Ketogenesis
Liver can convert Acteyl CoA into
Ketone bodies, small 3 or 4 carbon molecules soluble in the bloodstream which can be sent to tissues during periods of fasting (glucose used up)
3 main ketone bodies:
- acetoacetate - one to know
- acetone
- D-B-hydroxybutyrate
Ketoacidosis
Caused by excess of acetoacetate and D-B-hydroxybutyrate in bloodstream (created by liver via ketogenesis)
- lowered blood pH
- common in diabetics
Lipids have greater energy density than carbohydrates or proteins
Require more oxidation (glucose is already more oxidized)
Carbohydrates better for quick energy
Functions of Fat
Stores energy in adipose tissue
Insulates body
Generates body heat (brown fat)
Fatty Acid synthesis
1st step
Occurs in the cytosol
- Acetyl CoA is activated to malonyl CoA (addition of carboxyl group)
- An acetyl CoA group and malonyl CoA group are “loaded” onto ACP of fatty acid synthase
Fatty Acid synthesis elongation phase
2nd step
Multiple reactions that produce fatty acyl still bonded to ACP of fatty acid synthase
- requires NADPH from Pentose Phosphate Pathway
Acyl carrier protein (ACP) transports the growing fatty acid chain between enzyme domains of fatty acid synthase (FAS) during biosynthesis
Repeated many times, each time added two carbons to chain until it yields 16 carbon fatty acid Palmitic Acid
- then, released from ACP site
Only fatty acid that can be produced naturally through fatty acid synthesis
16 carbon Palmitic acid
Cholesterol Synthesis
1st step
Sterol- type of lipid that helps maintain cell structure and fluidity and **precursor of steroid hormones
Similar to fatty acid- starts in cytosol and uses acteyl CoA as precursor
-
Continues in endoplasmic reticulum (ER)
- 3 acetyl CoA’s condense to form 6-carbon mevalonate
- uses 2 NADPH, rate-limiting step
Cholesterol Synthesis 2nd step
3 molecules of ATP used to transform mevalonate into two activated isoprene molecules
- 6 isoprene molecules condense to form squalene which goes on to form cholesterol
Cholesterol from liver delivered via bloodstream to tissues within LDL lipoproteins
phospholipids are formed from
Fatty acids and diacylglycerols (DAG)
Dispositional Attributions
Behavior explained by inherent disposition in character
ex. brandon acted that way because he’s a stellar human being
* can be positive or negative
Situational Attribution
Behavior explained by external factors or circumstances
ex. the customer was rude because he was having a bad day
Cues
Consistency Cues
Dinstinctiveness Cues
Consensus cues
Decide whether someone is behaving that way dispositionally or situationally
Cues that focus on individuals’ behavior over time\
Cues that focus on individuals’ unique behavior in similar situations
Cues that focus on individuals behavior in relation to societal expectations
Actor Observer Bias
Attributing negative behavior as dispositional for others but situational for oneself
- more aware of ones situation than anothers
- more readily label others negatively
Fundamental Attribution Error
Attributing negative behavior of others to their disposition rather than situation
- different from actor observer bias because doesn’t mention oneself
Self Serving Bias
More likely to make dispositional attributions of our own positive behavior and situational attributions to our negative behavior
Locus of Control: Internal and External
internal locus of control: degree to which people believe they do have control over the outcomes of events in their lives
external locus of control: degree to which people believe they don’t have control of outcomes of events
Halo effect
Tendency for an impression in one area to influence the opinion of another
part of why people dress up for interviews
Just-World Hypothesis
The assumption that a persons actions inherently bring morally fair and fitting consequences
ex. good things happen to good people
Collectivistic Cultures (China, Japan, South Korea) are more likely to make
Individualistic cultures (US, England, Spain) more likely to make
situational attributions
dispositional attributions
Prejudice
Irrational attitudes (positive or negative) towards various groups or even objects
- affective/emotional response, not thought out like a stereotype
an assumption or an opinion about someone simply based on that person’s membership to a particular group
Stereotypes
Contentful- what we assume about people
- Cognitive- as opposed to prejudice which is emotion-based
a widely held but fixed and oversimplified image or idea of a particular type of person or thing.
Discrimination
Requires action, someone treated differently based on prejudices regarding membership in a group
- almost always negative
- few, if any, limits on what the actions are
- communication, making opportunity available
Has to involve actions or outcomes
Individual vs. Institutional Discrimination
Individual: ways in which a single person can treat other people differently based on group membership
Institutional: larger patterns of unequal behavior or outcomes, as mediated by entire institutions
- racial segregation
- job applications
- education gaps
- health care
Contributing factors to prejudice, stereotype, discrimination
Race, ethnicity, religion, gender, sexual orientation, age
Self-fulfilling prophecy
Occurs when self-perceptions (often influenced by external factors) cause specific behaviors
- people can pick up on stereotypes that apply to them and act accordingly
Stereotype Threat
Occurs when members of a social group are or feel at risk of conforming to stereotypes of their group
- even being reminded of someones stereotypes can affect performance
Stereotype Boost
Occurs when members of a social group are or feel empowered by stereotypes of their group
Stigma
Strong societal disapproval of groups, identities, or behaviors
Ethnocentrism vs Cultural Relativism
Ethnocentrism: Evaltuation of other cultures according to preconceptions of ones own culture
Cultural Relativism: belief that a person’s practices and values should be evaluated based on their culture, rather than anothers
- Put in mental effort to understand ritual/behavior
Demography
Demographic categories
Field of sociology dealing with categories we use to describe people
Age, gender, ethnicity, race, immigration status, sexual orientation
Age
Associated with broad range of physical and psychological changes
- different stages of life associated with different societal roles
Elderly: some cultures view them as highly respected community members; continue to live with extended families as long as possible
- in america, elderly people encouraged to live with other elderly people
Generations
Categorizing age by cohorts
Sex and Gender
Gender Schema, Gender script
- Sex is biological, male or female
- Gender is a social construct; gender roles vary across societies, change over time
Gender schema: what we consider to constitute maleness and femaleness
- ideas about gender that may lie at the root of a gender script
Gender scripts: more concrete, refer to specific expectations about how an individual of a given gender is expected to act in a given situation
Gender Segregation
Social insitutions where people are separated by gender
Sexual Orientation
Who people are attracted to
- homosexuality, heterosexuality, bisexuality
Race
Human categorization based on physical characteristics associated with certain populations
Official US categories:
- white american
- black/african american
- native american
- alaska native
- asian american
- native hawaiian
Racialization
Race Formation Theory
When racial identity is imposed on a person
Processes of racialization are deployed by power structures in society to advance political or social goals
Ethnicity
Refers to someones cultural background
- language is associated
Immigration Status
Not a yes/no category; someone can be a:
- resident
- visa holder- time limits, occupational restrictions
- permanent resident- can’t vote but few restrictions
- undocumented immigrant
Perceptions of immigration linked to perceptions of race/ethnicity
Emigration- migration out of a country
Thomas Robert Malthus
First researcher to think about population changes, didn’t think large population would be sustainable
Demographic Transition
Stage 1: death rate and birth rate are high; stable or slow increase
Stage 2: birth rate remains high, death rate falls rapidly
- very rapid increase in pop
Stage 3: death rate still decreasing, birth rate falling
- increases in pop slow down
Stage 4: both slow, growth is stable
Possible stage 5, decreasing population and increasing age
Population Pyramid
Dependency Ratio
Visualize balance of age and gender groups in society
Dependency ratio = [(# of ppl 0-14)+(# of ppl 65+)] / (# of ppl 15-64)
- Rough estimate of number of people workforce must support
Crude birth or death rate =
= (births or deathers per year)/ population x 1000
- births/deaths per 1000 people
Fertility rate
Lifetime births / woman
Great Depression
1929-1939; serious deprivation and poverty, lasting impact on generational cohorts
Migration in the US
Push factors
Pull factors
Periods of heavy and light migration in the US
- very common in late 1800s early 1900s
- 1920s had laws put in places, reformed in 1960s which led to more immigration again
Push Factors: poverty, war, violence
Pull Factors: economic prosperity, social stability
Globalization
Ever-closer economic and cultural linkages
- due to technical advances, communication technology makes intercontinental coordination and cultural diffusion possible
Could have negative impacts on viability of smaller cultures and languages, possibly civil unrest and terrorism
World Systems Theory
Divides world into core, semi-peripheral, and peripheral nations based on place they occupy in global economy
- core nations specialize in higher skill labor, capital investment
- peripheral- lower skill production that is labor intensive
Urbanization
Suburbanization
1st stages driven by industrial revolution, dramatic transformation in manufacturing technologies in late 1700s to mid 1800s in England and the US
- associated with dramatic growth of urban centers
Suburbanization: large amounts of lower-density housing built outside of cities
- wealthy families moved out of cities due to single family housing, large backyards, easy commute to city and away from crime
- led to urban decay
Gentrification
Reversal of trends of suburbanization and urban decay, well off families moving back to cities – urban renewal
Gentrification: displacement of lower income working class communities from neighborhoods with deep roots
- local gov’t tax base increases but existing residents at high risk for displacement
Social movements
Relative Deprivations
Proactive: seek to make a certain change happen
Reactive: seek to prevent change
- letter writing campaigns, protests, direct action
Relative reprivation: person or group lacks certain resources in comparison to other groups in society
- relative poverty vs. absolute poverty
Social Classes
Characterized by similar economic situations, access to opportunities, cultural attitudes
- Upper- wealthy and powerful
-
Middle-
- upper middle- usually work for a salary, earn enough to live comfortable life with luxuries
- middle middle
- lower middle- work lower salary jobs or well paying hourly, more vulnerable to hardship
- Lower (working class)- work low paying, hourly jobs. economic insecurity, limited access to opportunities
Not the only way societies can be stratified
Can also differ by how changeable statuses are over time
Quaternary Protein Structure
Mutiple protein subunits/polypeptides
- held together by same interactions that maintain tertiary structure (H-bonds, salt bridges, disulfide bonds)
Homo = identical subunits
Hetero= nonidentical
ex. heterotrimer, homotetramer
Protein folding is
spontaneous and thermodynamically favorable
Enzymes
Biological catalysts that speed up reactions necessary for life by reducing the activation energy
- sensitive to temp and pH
- specific to reactions
Don’t change or get consumed, don’t affect Keq of rxn or other thermodynamic parameters (∆G, ∆H, ∆S, spontaneity)
- also speeds up reverse reaction
Exergonic vs. energonic reaction coordinate diagram
Substrate
Substance an enzyme acts on
Active site ON ENZYME is comprised of
Catalytic site: where reaction is catalyzed
Binding site: large area where substrate interacts with enzyme by intermolecular interactions (H-bond, dipole-dipole, london disperson)
- positions substrate properly relative to catalytic site
Lock and Key theory (enzyme and substrate)
Fit together with no change in tertiary, quaternary structure
- oversimplification
Enzyme and substrate “Induced fit” theory
More realistic than “lock and key”, enzyme and substrate induce conformational shifts, closer binding
Ligand
Regulatory molecules and substrates
- any substance an enzyme interacts with
Orthosteric regulation
Interacts with enzyme at active site
Allosteric regulation
“allo” means different
- Interact at other site on enzyme
Classifications of Enzymes (based on mechanisms)
6 types
All enzymes end in -ase
- Oxidoreductases catalyze oxidation reduction reactions
- Transferases: transfer a functional group b/w molecules
- Hydrolases: catalyze hydrolysis
- Isomerases: catalyze isomerization
- Lyases- cleave bonds not using hydrolysis (ex. glycolysis)
- Ligases- Join molecules with covalent bonds
Oxidoreductases
catalyze oxidation reduction reactions
Transferases:
transfer a functional group b/w molecules
Hydrolases:
catalyze hydrolysis
Isomerases:
catalyze isomerization
Lyases-
cleave bonds not using hydrolysis (ex. glycolysis)
Ligases
an enzyme that uses ATP to form bonds
- ex. DNA ligase
ex. alcohol dehydrogenase
ex. Lactase
Catalyzes ethanol to acetaldehyde, ethanol metabolism
** Alcohol is substrate, dehydrogenase is action (oxidoreductase)
Breaks down lactose through hydrolysis
Phosphotases
Removes phosphate group from substrate
Kinases
Adds phosphate group through phosphorylation
Coordination of enzymes is important so that the reaction
Happens at the right rate, amount and time
Feedback (negative and positive)
Downstream product of a pathway reaches backwards to regulate upstream paths
Negative feedback/inhibition
Examples
Downstream product makes previous step less likely or efficient
- downregulation
ex. Body temp regulation
Glycolysis committed rate limiting step: PFK-1 catalyzes addition of phosphate group (regulated by product, ATP)
Positive feedback examples
Oxytocin stimulating uterine contractions which releases more oxytocin, ends with birth
Blood clot formation requires positive and negative feedback
Feed Forward Regulation
Upstream product in higher concentration catalyzes downstream reaction
ex. In glycolysis, pyruvate kinase catalyzes ATP producing rxn, enzyme activated by intermediate fructase 1,6-bisphosphate upstream
Cooperativity and Hill coefficients
Enzymes can have multiple active sites for the same ligand, binding at one active site can make it easier to bind at another
- > 1 is positive cooperativity
- 0 is none
- < 1 is negative cooperativity
Hemoglobin
Transports metalloprotein which transports oxygen throughout the body
- Has 4 subunits which each can bind one oxygen molecule
- Uses cooperativity, easier to bind the next oxygen
Factors for hemoglobin saturation:
- Oxygen in the environment
- Ease of contact with O2 and hemoglobin binding sites
Posttranslational covalent modifications of proteins
phosphorylation, glycosylation, ubiquitination, nitrosylation, methylation, acetylation, lipidation and proteolysis
Enzyme-substrate interactions are non-covalent (uses polarity/sterics)
Enzyme-substrate interactions are
non-covalent (use polarity of sterics)
Phosphorylation
Attaching a phosphate group to a compound (ENZYME): affects its activity (activated or deactivated)
- most commonly targets serine residues as well as threonine and tyrosine
- side chains have OH groups a phosphate can attach to
Reversible
Posttranslational Modification: Cleavage of covalent bonds
Often times, used for zymogens: inactive precursor for enzymes
ex. Trypsinogen released from pancreas is cleaved into active trypsin; if active enzyme was in pancreas it’d digest itself
Some enzymes require another compound to be present to function:
Cofactors/Coenzymes
Cofactors:
Inorganic (Mg, Cu, Zn) or organic (coenzymes)
- Required for normal function
Coenzymes
Often vitamins or vitamin derivatives
Often contribute to function of enzymes by carrying functional groups from one place to another in a reaction
- ex. Coenzyme A (CoA) transfers acyl groups
Prosthetic groups
Coenzymes tightly or covalently bonded to their enzymes
- ex. Heme attached to O2 transporters like hemoglobin or myoglobin
Holoenzyme
Enzyme together with what it needs to be functional (coenzymes, cofactor)
Apoenzymes
Enzymes without cofactors needed to function properly
Michaelis Menten Model (Vmax and Km definitions)
100 molcules of enzyme X in a test tubel enzyme X catalyzes conversion of S –> P
- Vmax: MAX RATE, saturated, all molcules of X occupied
-
Km: conc of substrate (S) at HALF of Vmax
- how readily enzyme reacts w/ substrate
-
Km: conc of substrate (S) at HALF of Vmax
V = Vmax [S] / Km + [S]
Km
Concentration of substrate that corresponds to half of Vmax
- High Km= enzyme has low affinity for substrate
The less substrate they need to reach half of their maximum speed, the more efficient they are. So if the Km is low, you have a really efficient enzyme. If the Km is high, the enzyme is much less efficient.
Lineweaver-Burk Plots
Double reciprocal transformation of Michaelis Menten plots to make estimating Vmax and Km more precise
Competitive inhibitors
Compete with substrate for the active site
-
Don’t affect Vmax because they can be outcompeted by adding substrate
- effect can become negligible
-
DO affect Km because they can be overcome with extra substrate
- more substrate to reach Vmax
- increases Km
Noncompetitive Inhibition
Interacts with enzyme allosterically (not at active site), can interact with enzyme regardless if bound to substrate
- prevent enzyme from working similar to reducing amount of enzyme present
reduces Vmax
Km stays same
Uncompetitive Inhibitors
Prevent enzyme from converting substrate to product
- Allosteric
- Prevent enzyme from letting go of substrate
Reduce rate of catalyzed rxn, Vmax decreased
Km decreased, enzyme has greater affinity for substrate
Mixed Inhibitors
Can bind to free enzyme (no substrate bound) of enzyme-substrate complex
- Decreases Vmax
Km depends on binding preference, increases when bound to free enzyme
Nucleoside
Nucleotide minus phosphate group
Nucleotides can have more than one
Phosphate group, like ATP
cAMP
Cyclic adenosine monophosphate - chemical signalling molecule
Pyrimidines
One ring, cytosine and thymine and uracil
CUT the Py
Purines
Two rings, adenine and guanine
Shorter word, more rings
Caste System
Status is generally inherited
- Characteristic of south Asian societies, some central European
Social and Cultural Captial
Class isn’t all about money
Social capital: the “wealth” someone has through their social network and contacts
Cultural capital: traits that signal membership in a higher class
- includes attire, belief, customs
Class Consciousness
False Consciousness
Identifying as a member of one’s economic class
- advocating for the rights/interests of that class
Focusing on other parts of identity, while not identifying with their own class
- buying into incorrect ideas about social class or mobility
Social Inequalities (3 p’s)
Intersectionality
Power- ability to get things done; controlling resources and influencing others action
Prestige- certain things are associated with a higher level of society
Privilege- favorable assumptions due to features beyond ones control
- ex. racial privilege with police
Intersectionality- experience of combined social stratification, often not equal to the sum of their parts
- social experience of a black woman isn’t that of a black person + a woman
Absolute or Relative Poverty
Absolute poverty- when someone is not able to obtain the basic necessities of life
- income threshold depends on place
- material conditions of absolute poverty are universal
Relative poverty- poverty relative to other members of one’s community
- We compare ourselves to people in our reference groups
Marginal vs. Structural Poverty
Marginal poverty- wealth inequality caused by the lack of stable employment
Structural Poverty- wealth inequality influenced by the way society is structured
Social Exclusion
Experiences of poor people not well recognized by mainstream society
- less access to resources, opportunities, rights
Results in isolation, contributes to persistence of poverty
Spatial inequality
Residential segregation: people of certain demographics cluster together
- caused by:
- legal and quasi-legal regulations
- discriminatory lending practices
People also choose to live by people like them
- Disparities in qualities of public schools
- Differences in safety and violence across neighborhoods
Environmental risk factors for diseases not distributed equally
Social Reproduction
The structures and patterns of society that cause inequalities to become passed down from one generation to the next
- inequality over time!!
Global Inequality examples
Gini index
Life expectancy, income, safe water, healthcare, education
Measuring the extent to which wealth is concentrated among a few people within a society
Incidence vs. Prevalence
Prevalence: a snapshot of how common a given condition is in a population
Incidence: how many new cases occur among an at-risk population over a certain amount of time
Socioeconomic cause of health/health care inequality
Poorer people have worse health and access to quality health care
- affordable care act (obamacare) and medicaid attempt to rectify these inequalities
Lack of access, lack of quality of care, lack of access to healthy food, exposure to environmental risk factors
Race and ethnicity in health/health care inequalities
Biological differences in health
Variation by race in where melanoma develops
Race/ethnicity contribute to broad health trends
- asians have best health
- African-american and native american have worst
Sex health inequalities
Women tend to live longer than men (in affluent, industrialized societies)
- estrogen levels reduce cardiovascular disease
- unequal distribution of risk factors (men smoke, drink more)
*
Variations in the degree that people feel they are receiving understanding, compassionate health care
Providers need to be aware of patients specific needs
Intergenerational Social Mobility vs Intragenerational mobility
Intergenerational: Changes in social status across generations
Intragenerational mobility: Takes place within one generation
Horizontal vs. Vertical social mobility
Horizontal: switching roles within a single class
- ex. electrician to carpenter
Vertical: moving to a higher or lower stratum of socioeconomic heirarchy
- exchange mobility: when someone moves up socioeconomic ladder, someone else moves down
- structural mobility: dramatic changes to society can either enrich or impoverish many people at once (Great Depression)
Meritocracy
More capable people are able to experience more success
- unequal outcomes based on equal opportunities
- same access to prove capabilities
Sound is caused by
How do we perceive it
Vibrations of molecules that travel as pressure waves through a medium
- displacement of molecules due to longitudinal (compression) waves
We perceive sound due to vibrations of air molecules detected by bones in ear and turned into action potentials
What makes sounds “sound” different
Speed- most strongly affected by medium through which it travels
Amplitude-
Frequency-
Speed of sound is affected by
Speed of sound equation
affected by medium through which it travels, fastest through incompressible material
- fastest through solids, slowest through gases
Also affected by density of medium: more dense = slower
bulk modulus (B): a material’s resistance to compression
V = √(B/P)
speed of sound = sq rt of bulk modulus / density
Quality of pitch of a sound is determined by
How do we perceive the loudness of sound? Determined by?
Frequency (Hz)
- high freq = high pitch
Pitch is a psychological phenomenon
Intensity- determined by amplitude of sound wave
- measured on decibel scale (dB)
-
dB = 10log (I/Io)
- Io is faintest intensity we can hear a sound
Attenuation: Intensity of sound decresases over time as energy dissipates
Doppler effect
Occurs when source of sound moves relative to observer or the observer moves relative to the sound
- ex. ambulance emits constant frequency in all directions; as it travels toward you, sound waves in front of vehicle get compressed –> perceived as higher frequency
Sound waves behind the vehicle get spread out, lower frequency
Doppler effect equation
f’ (perceived freq) = fo ( Vsound + Vobserver / Vsound + Vsource )
- fo = freq of source
- Vsound is velocity of sound through a given medium (constant)
If either observer or source are stationary, V = 0
Vobserver is positive if moving towards source
Vsource is positive if moving away from observer
Doppler Ultrasound
High freq Sound waves are emitted and time taken to reflect back can be used to produce images
Light shows wave-like behavior and particle-like behavior
Wave-particle duality
Light as a wave is termed an
Electrical and magnetic components relative to velocity (directional) component
Electromagnetic wave (transverse waves)
- can propagate through air/water but also a vacuum
Electrical and magnetic components, each perpendicular to each other and both perpendicular to the velocity component
Electromagnetic radiation
Light is made up of many collective electromagnetic waves
- waves are randomly polarized (electric/magnetic components can be pointing any direction)
- polarizing filter is a tool than can be used to linearly polarize light - only allows correctly oriented light to pass (polarized sunglasses)
Polarizing filter - circular polarization
Polarization where direction of electric and magnetic fields rotate steadily over time
- Right-handed or Left-handed
Used in optical dichroism to determine chirality
Electromagnetic Spectrum
Places each form of EM radiation on a scale according to frequency and wavelength
- gamma rays (low freq), X rays, UV rays, visible light, infrared, microwave, radio waves
Visible light spectrum
Wheres red, wheres violet
Described in terms of wavelength (nm)
- ranges from 400 nm to 750 nm
Red light is high wavelength - INFRA red
Violet is short wavelength- ULTRA violet
Spectrometry
Absorbance
Used to measure the degree to which a substance absorbs different wavelengths of EM radiation
Used to track progress of reaction or guage purity of solution
Absorbance: the absorption of certain wavelengths of light
Reflection
Bounces of surface of mirror at an angle symmetrical to angle of incidence
- relative to line perpendicular to the surface = normal line
Refraction
Refractive Index (n)
If wave travels from one medium into another
- changes speed of waves and bends the light
Light only refracts when it hits medium at an angle
n = c / v
- c = speed of light in a vacuum
- v = light speed in medium
n is always greater than 1; nair is pretty much 1
Snell’s Law for wave refraction
n1sinΘ1 = n2sinΘ2
When light travels from a faster medium to a slower one, the angle gets smaller
Total internal reflection
If angle of incidence is large enough when passing from one medium to another it can reach critical angle, where it reflects
- Light has to be moving from high n to low n
- Angle of incidence is large
Dispersion of light
Light with a longer wavelength (like red light) doesn’t change speed or bend as much as that with a shorter wavelength when passing into a new medium
- light rays passing through a glass prism
Diffraction
Waves encounter a barrier with a small opening
- waves that hit the barrier are reflected back while waves that hit opening expand outward
Constructive/destructive interference leads to areas of intensity (maxima) and dark regions known as minima
Single slit diffraction
One aperture (hole)
AsinΘ = mλ
A = size of aperture
Θ= angle relative to original light beam
m = nth minimum
Double slit diffraction
Hole width is negligible, D = distance between the slits
- Compared to single slit, minima and maxima are much more evenly distributed
DsinΘ = nλ
n = nth MAXIMUM
Maxima are at whole number integers, minima are at half
Thin Film Interference
Light waves reflect off top and bottom boundaries of a substance that forms a thin film
Erikson’s Stages of Development
Proposed life is a series of stages each with a conflict to resolve; resolving these successfully leads to healthy development
- trust vs. mistrust (0-1): based on interactions with caregivers, child has trusting or mistrusting attitude towards world
- autonomy vs. shame/doubt (1-3): children begin actively exploring, support decides whether they feel independent or doubtful
- initiative vs. guilt (3-6): children start working on goals and feel good or guilty about them
- industry vs inferiority (6-12): children have various tasks and either are successful or unsuccessful
- identity vs role confusion (12-20)
6. intimacy vs. isolation (20-39)
7. generativity vs. stagnation (40-65)
8. integrity vs. despair (65+): life been worth it?
Kohlberg’s Stages of Development
How people reason about moral choices provides information about how they view themselves
-
Preconventional- childhood
- Obedience- self oriented perspective that focused on negative consequences for breaking a rule
- Self-interest- self oriented perspective focused on benefits/rewards
-
Conventional- adolescence, begins to incorporate perspectives of others
- Conformity- concerned with approval of others based on social expectations
- Law and order- the understanding that social expectations and rules help ensure a stable society as a whole
-
Postconventional- adulthood
- Social construct- Laws are seen as ways to reinforce the greater good through a complex network of interrelated rights and responsibilities
- Universal human ethics- individuals can make abstract judgements and engage in reasoning based on justice
Freudian Psychology (3 components of human psyche)
Psychoanalytic perspective
Human psyche is 3 components:
Id- bundle of basic unconscious urges: survival, reproduction, immediate gratification
- the pleasure principle
Ego- component of personality that interracts with the world, makes decisions
- the reality principle
Superego- what we are supposed to do, ideal version of ourselves
- drives us to perfectionism and socially internalized ideals
Freud’s coping mechanisms for stress
Regression- returning to an earlier developmental stage
Reaction formation- an unconscious transmutation of unacceptable desires into their opposite
Displacement- transferring a desire from an unacceptable object to a more acceptable one
Sublimation: the redirection of desires that are felt to be unacceptable or inappropriate into another behavior
Projection: individual attributes unwated or uncomfortable feelings towards someone else
Rationalization: coming up with excuses for feelings or behaviors we feel are problematic
Suppression: conscious attempts to disregard uncomfortable feelings
Repression: unconscious suppression of uncomfortable feelings
Freud’s psychosexual perspective
The human libido persists throughout life; children develop through five stages of life centered around diff body parts
1. Oral (0-1)- pleasure from feeding and exploring world through their mouths
- fixation leads to immature, passive personality with oral tics
2. Anal (1-3)- children learn to control bladder/bowels
- frustration or fixation can lead to anal-retentive personality or anal-repulsive personality (defiance)
3. Phallic (3-6)- children aware of own genitalia and those of others
- Boy experience “Oedipus complex” and want to possess mothers
- Girls experience “Electra complex”
4. Latency (6-puberty)- sexual urges into dormancy
5. Genital (puberty-death)- libido is focused on their genitals
Carl Jung (Freud’s student)
Humans are able to access a collective unconscious that contains various archetypes
Behaviorism (who founded it)
B.F. Skinner (1930): Observable behavior and learning comprise the sole reliable sources of knowledge about humans
- everything boils down to reflexes or conditional learning; rejection of emotions and self-image
Humanistic psychology perspective (who was associated, what was it)
Emphasizes importance of empathy as a therapeutic technique
- unconditional positive regard (Carl Rogers): therapist accepts the client completely and verbalizes it
Interest in self-actualization: ability of people to fully live up to their personality
Leads to Maslow’s heirarchy of needs
Trait theories for personality development
Reduce personalities into a limited set of traits that combine in different ways
Characterize people by The Big Five Theory:
- Openness
- Conscientiousness
- Extraversion- outgoing and socialness
- Agreeableness
- Neuroticism- the degree to which a person experiences intense emotion in stressful situations
Considered more valid due to factor analysis
Or PEN Theory (Hans and Sybil Eysenck)
- Pyschoticism
- Extraversion
- Neuroticism
Type theories for classifying personality
Astrology- categorize people based on when they were born
Type A vs. Type B personalities
Myers-Brigg type inventory
Social Cognitive perspective of personality (who, what)
Promoted by Bandura
- Reciprocal determinism: our behaviors, choices, and personalities influence each other
Learning from other people is essential
Biological perspective for personality
Genetic factors shape personality
Symbolic interaction (who, what)
George Herbert Mead
- Pyschological development is interplay between “I” internal self and “me” the version of self the environment reflects
The “more knowledgeable other” (who, what)
Lev Vygotsky
- focused on cognition and personality
- role of others in how sense of self is shaped
Two approaches for analyzing psychological disorders
Biomedical approach- disorders are physcially-based conditions
Biopsychosocial appraoch- still recognizes biological causative factors but emphasizes role played psychological and sociological factors
- ex. emotions, self-concept
- ex. presence of social support, social stigma with mental illness
How is a psychological disorder defined?
What % of population is thought to have mental disorder?
Mental or behavioral pattern causing distress to a person or impairing their ability to function within society
Approx 1/4 of population is thought to have disorder
Where are psychological disorders defined?
Classified in DSM-5: the definitive source for classification and definition of psychological disorders
- based on their symptoms
Definitions of disorders are culture specific
The understanding of such disorders can change over time (even within the same culture)
Types of psychological disorders
- Depressive disorders
- Bi-polar disorders
- Anxiety disorders
- Obsessive-compulsive disorders
- Trauma and stress-related disorders
- Conversion disorders
- Schizophrenia
- Dissociative disorders
- Personality disorders
Depressive disorders
Symptoms of a major depressive episode
Major depressive disorder: defined by presence of at least one major depressive episode: two week period including 5 or more of the following symptoms:
- intense sadness/depressed mood
- Anhedonia: lack of interest in activities previously thought to be enjoyable
- weight changes
- sleep disturbances
- appetite disturbances
- Feelings of guilt or worthlessness
- reduced energy
- Psychomotor symptoms
- Difficulty in focusing attention
- Suicidal ideation/attempt
Dysthymia: less intense form of depression
- must occur for at least two years
Persistent depressive disorder: experience significant depressive symptoms for over two years
Seasonal Affective Disorder: major depressive disorder with seasonal pattern of onset, usually during winter months
Bipolar I, II, cyclothymic disorders
Manic episode?
Bipolar I: primarily characterized by mania, can also have depressive disorders
Bipolar II: primarily characterized by depression - one major depressive episode
- hypomania: less intense mania that may not interfere with function
Cyclothymic disorder: similar to bipolar II, involves hypomania but lower intensity of depression
manic episode: a period lasting at least one week during which a person experiences unusally elevated mood and at least 3 of following symptoms:
- Grandiosity or unrealistically inflated self esteem (sometimes to point of delusions)
- Reduced need for sleep
- High levels of distractability
- Agitation
- Rapid speech or abnormal loquaciousness
- Flights of ideas or racing thoughts
- Tendency to engage in high-risk behavior
- may also involve psychosis (losing contact with reality)
Anxiety Disorders
Generalized Anxiety Disorder: disproportionate stress and worry regarding a diverse range of otherwise routine aspects of life
Social anxiety disorder: intense feelings of stress linked to social situations
- fear of embarrassment
Illness anxiety disorder (hypochondria): excessive concern bout medical conditions in the absence of physical symptoms
Phobias: fall into category of anxiety disorders
Anxiety disorders are different than just not liking something
- can be functionally debilitating
- involve sympathetic response - fast heart rate, sweating, trembling
- panic attacks, hyperventilation, sense of impending doom
Panic disorder: persisting panic attacks
Obsessive-compulsive disorder (OCD)
Body Dysmorphic Disorder
used to be under anxiety disorders
Consists of obsessions and compulsions
- obsessions: intrusive, impulsive and persistent thoughts
-
compulsions: ritualistic and repetitive behaviors that result from those obsessions
- temporary way to gain relief from the anxiety induced by obsessions
Body dysmorphic disorder: obsessive focus on a perceived flaw in one’s appearance that is objectively minor or nonexistent
Trauma and Stress-related disorders
Post traumatic stress disorder: occurs in people exposed to intense acute or chronic trauma
- pattern of intrusive recollections
- avoidance of stimuli related to trauma
- negative changes in mood or cognition related to the traumatic event
- altered patterns or reactivity and arousal
Somatic disorders
Involve physical symptoms
Somatic symptom disorder: excessive preoccupation or focus on a physical symptom
Conversion disorder: physical symptoms involving the impairment of sensory or voluntary motor function with no apparent biological cause
- onset usually shortly after traumatic event
Dissociative disorders (used to be under anxiety disorders)
Disconnection from one’s routine state of consciousness and/or personality
Dissociative Identity Disorder: individual has two or more distinct personalities that appear at different times
- tends to occur in people subjected to extreme trauma
Dissociative amnesia: a form of retrograde amnesia in which people lose episodic memories about their lives
Depersonalization/Derealization disorder: Pattern in which people feel sense of unreality about their existence
Schizophrenia symptoms (two types of symptoms)
Psychotic disorder characterized by Positive Symptoms (addition of something extra onto baseline patterns)
- hallucinations
- delusions
- disorganized thought and behavior
- catatonia: abnormal movement patterns
and Negative Symptoms (absence of aspects of one’s baseline epxerience):
- diminished levels of emotional intensity/intitiative
Schizophrenia development
Peak age for men and women is early 20s
- may develop later in life, especially in women
- rare beyond age of 50
- development may be preceded by prodromal phase:
- person displays pattern of poor social adjustment and integration
Recently schizophrenia has been conceptualized as a spectrum
Schizophrenia treatment
Antipsychotic (neuroleptic) medications as well as some therapy
Positive symptoms of schizophrenia
what are hallucinations?
what are delusions? types of delusions?
Positive Symptoms (addition of something extra onto baseline patterns)
-
hallucinations
- Perception of non-existent external sensory stimulus
- most common are auditory hallucinations
-
delusions
-
beliefs that conflict with reality or do not reflect a broader cultural consensus
- tend to persist regardless of contrary evidence
- delusions of persecution: powerful forces are acting against the persons best interests
- delusions of grandeur: outsized belief in ones exceptional nature
- thought insertion: the belief that thoughts can be transmitted into your head
- thought broadcasting: belief that your thoughts are visible to others
- delusions of reference: belief that aspects of the publicly-available external environment are specifically targeted towards you
-
beliefs that conflict with reality or do not reflect a broader cultural consensus
-
disorganized thought and behavior
-
refer to a level of disability that makes interactions with outside world diffcult
- challenges with hygeine
- erratic patterns of interactions with others
- speech difficult to understand
-
refer to a level of disability that makes interactions with outside world diffcult
-
catatonia: abnormal movement patterns
- energy consuming but unusual movements that occur without a specific external cause
- tendency to repeat others actions/words
- tendency to be lethargic
Negative Symptoms (absence of aspects of one’s baseline epxerience):
Diminished levels of emotional intensity/intitiative
- Disturbance of affect
- how emotion is expressed
- may be blunted or flat
- mismatch with social conventions
- how emotion is expressed
Personality Disorders
10 personality disorders in 3 subtypes
Maladaptive behavioral patterns that cause consistent problems in a person’s life
- may not be recognized as a problem by affected person
Important not to overdiagnose these disorders, risk medicalizing benign variations in human behavior
- cannot be conclusively diagnosed in people under 18 years of age
- personality thought to not fully crystallize until adulthood
Subtypes Cluster A, B, C
Cluster A personality disorders
-
Paranoid Personality disorder-
- high level of distrust in others, jealousy, tendency to interpret innocent actions as having malevolent intent
-
Schizoid- marked preference for solitude
- tendency to form few relationships
-
Schizotypal
- intense discomfort in social contexts
- unusual beliefs not quite delusions
Cluster B personality disorders
-
Antisocial- pervasive pattern of disregard for rights of others
- often violent behaviors and lack of remorse
-
Narcisstic- pervasive sense of one’s unique talents, brilliance, and attractiveness
- fantasies about unlimited success and power
- shallow, conflict-driven relationships
- may be caused by lack of self esteem and need for validation
-
Histrionic- pattern of flashy, attention seeking behavior
- exaggerated but perhaps not fully sincere emotions
-
Borderline- tendency for extremely intense but unstable emotions and moods
- Splitting: people are seen as either completely good or completely bad with no gray area
- Risky, impulsive behavior
Cluster C personality disorders (characterized by anxiety)
Avoidant- persistent sense of inadequacy and hypersensitivity to criticisim
- leads people to avoid social situations or challenges at school/workplace
Dependent- profound need to be taken care of by others
- very difficult to be alone
- elevated risk for victims of abusive relationships
Obsessive compulsive- distinct from OCD
- excessive concern with rules, order and regulations
- perfectionism
- controlling, inflexible, stubborn
Schizophrenia biological basis
Strong genetic component
- highly heritable
Excess levels of dopamine neurotransmitter
Parkinson’s disease biological basis
Symptoms: tremors, slow movements, loss of facial expressions, bent posture
Caused by cell death in substantia negra
- leads to reduced dopamine expression
Depression biological basis
Deficiency in neurotransmitters dopamine and serotonin
- Selective Serotonin Reuptake Inhibitors (SSRIs) are a major class of antidepressants
Alzheimer’s disease biological basis
Memory loss, emotional disturbances
- Clumps of beta-amyloid protein plaques and fribrillary tangles of tau proteins in the brain
- Reduced levels of neurotransmitter acetylcholine
4 major tissue types in body:
- Epithelial
2. Nervous
3. Muscle
4. Connective
Connective tissue
Connects tissue and organs
- bone, blood, adipose (fat), cartilage, ligaments, tendons
Connective tissue - cartilage
Composed of what cells?
Flexible, rubber-like tissue
- no nerves or blood vessels
Composed of chondrocytes, cells that make the protein collagen (structural protein that strengthens and connects tissues)
Endothelial cells
form a single cell layer that lines all blood vessels and regulates exchanges between the bloodstream and the surrounding tissues.
Signals from endothelial cells organize the growth and development of connective tissue cells that form the surrounding layers of the blood-vessel wall.
Collagen
Structural protein that strengthens and connects tissues
- most abundant protein in body
Found mostly in extracellular matrix (supporting meshwork cells sit in)
Connective tissue - tendons
Ligaments and tendons are bands of collagenous fibers
Ligaments- connect bone to bone
- “like to like” ligaments
Tendons- connect muscle to bone
- “two types” tendons
How many bones in human body?
206
Skeletal Categories
-
Axial
* vertical axis - skull and vertebral column, rib cage
2. Appendicular
- extremeties - pectoral girdle, pelvic girdle, upper extremity (arms), lower extremity (legs)
Axial Skeleton - skull
Made up of 22 bones - frontal, parietal, occipital, temporal bones
Axial skeleton - vertebral column
Has 24 vertebrae
- Cervical
- Thoracic
- Lumbar
Sacrum and coccyx are smaller
Appendicular skeleton - upper extremeties (arms) and lower extremeties (legs)
Arms: Humerous, radius and ulna
- if you face your palms forward, the ulna is closest to your body
Legs: femur (largest bone in body), tibia and fibula
- tibia is the shin bone, fibula is more slender and connects to the ankle
Bone Types - long bones
Long bones
- Central shaft is called diaphysis
- Ends of bone are called epiphysis
- in between the two is the epiphyseal plate, or growth plate
Growth occurs at growth plate until early adulthood
- growth occurs when cartilage is produced at epiphyseal plate, which gets replaced by bone - ossification
Bone types - flat bones
Flat, such as skull bones
Bone Types
Long bones
Flat bones (skull)
Short bones (hands and feet)
Sesamoid bones- embed with tendon
Irregular Bones- neck and spine
Bone Types- sesamoid bones
Bones embedded in tendons like patella bone of knee caps
Types of Joints
Places where bones meet - tons of joint types
- pivot, ball and socket, hinge, saddle, plane, condyloid
Synovial Joints: freely movable joints; two bones meet in synovial cavity- fibrous lubricated capsule
Fibrous Joints: holds two bones together with fibrous connective tissue
- ex. skull bones
Cartilaginous joints: made of cartilage
- ex. intervertebral dics
Noncellular bone structure
Bone matrix- network of collagen fibers, water, and crystallized minerals (hydroxyapatite- storage deposit for calcium and phosphate)
Bone cell types (4)
Bones contain epithelial, adipose, nerves, blood vessels but also bone cells:
Osteoprogenitor cells (stem cells
Osteoblasts
Osteoclasts
Osteocytes
Osteoblasts
Cells that create new bone by producing osteoid
- “build bone”
Regulated by osteoclasts
Osteoclasts
Break down bone
- ** Bone is a storage deposit for calcium; when there is an abundance, osteoblasts incorporate it into bone which makes it stronger and builds calcium storage
- osteoclasts get this back when calcium is needed
Blood calcium levels have to be finely tuned because muscles rely on precise calcium concentrations for muscle contractions
Osteocyte
Most common bone cell type
- retired osteoblasts that are relatively inert
Each resides in its own pocket of space known as a lacuna
- communicate through small channels running perpindicular to the Haversion canal known as canaliculi
- exchange nutrients and waste products through extensions of their cytoplasm
What hormones have roles in skeletal system?
1. Parathyroid (PTH)- released by parathyroid glands
- increases blood calcium
- promotes osteoclast bone resorption
- promotes absorption of dietary calcium in GI tract
2. Calcatriol- derivative of vitamin D which the body manufactured at the skin in response to UV light
- increases blood calcium
3. Calcitonin- secreted from thyroid gland in response to high blood calcium
- decreases blood calcium levels
- inhibits activity of osteoclasts
- reduce absorption of dietary calcium
Compact bone
fundamental unit?
Hard and dense; structural support and movements
- fundamental unit is the osteon: cylindrical structures composed of concentric rings of bone matrix
- in the center of the osteon is the Haversion canal through which bones blood and nerve supply pass
Spongey bone
“Trabecular or Cancellous”
- spongy interior and porous
- less dense and stiff
Holes in it for blood vessels and bone marrow
Bone marrow
2 varieties
Inside flat bones and heads of long bones lies tissue responsible for creating all our blood cells
-
Red marrow: production of all blood cells
- hematopoiesis (production of red blood cells) and production of white blood cells
- Yellow marrow: composed of adipocytes, storage deposit for adipose
Connected intricately with lymphatic system
Nervous System muscle types
Voluntary- muscles we have conscious control over
- help us move and express emotion
- controlled by the somatic branch of the peripheral nervous system
Involuntary- muscles we dont have control over
- controlled by autonomic NS
- sympathetic (fight or flight)
- parasympathetic (rest and digest)
- ex. GI tract, pupils, muscles lining blood vessels and the heart
Fasicle
Bundle of muscle cells encased in connective tissues
Muscle cells are also called
Myocytes or muscle fibers
Myocytes contain ___ which themselves contain
rod-like myofibrils which contain microfilaments of myosin and actin
- organized into repeating units called sarcomeres
Myocytes are composed of
What makes them unique
Normal cell components: mitochondria, lysosomes, etc.
- Also contain myofilaments: alternating polymers of thick filaments composed of protein myosin and thin filaments composed of protein actin
- coordinate to drive muscle contraction
What coordinates for muscle contraction?
Mysoin and actin - myofilament proteins
Cytoplasm of muscle fibers
Contains?
sarcoplasm
- contains stores of myoglobin and glycogen
Plasma membrane of muscle fibers?
Sarcolemma
Sacroplasmic reticulum
Is in direct contain with ____?
Smooth endoplasmic reticulum
- stores calcium ions
Is in direct contact with T-tubules: projections of the sarcolemma
Sarcomere
Repeating unit of actin and myosin fibers that is the fundamental unit of certain muscle types
Muscle types (3)
- Skeletal
2. Smooth
3. Cardiac
Skeletal muscles
Under voluntary control
- somatic branch of peripheral nervous system
Skeletal muscles are striated =appear striped under a microscope due tosarcomeres (microscopic units of muscle fibers that do work of contraction)
Multinucleate
Do all cells have just one nucleus?
Skeletal muscles are multinucleate- result of several muscle fibers fusing together and combining their forces
- do so to create larger bulkier stronger muscle cells with multiple nuclei
Skeletal muscle subtypes
-
Slow twitch fibers: RED because packed with myoglobin, the oxygen grabbing protein in muscle
- also contain tons of mitochondria to generate ATP through oxidative metabolism
-
Fast twitch fibers: WHITE fibers, contract quickly but also fatigue quickly
- white because less densely packed with myoglobin and mitochondria
- use a different method to generate ATP
Slow twitch fibers:
RED because packed with myoglobin, the oxygen grabbing protein in muscle
- also contain tons of mitochondria to generate ATP through oxidative metabolism
Fast twitch fibers:
How do they generate ATP
WHITE fibers, contract quickly but also fatigue quickly
- white because less densely packed with myoglobin and mitochondria
- use a different method to generate ATP
**Generate ATP through anaerobic metabolism - glycolysis followed by lactic acid fermentation
Where is Smooth muscle
- Line digestive tract for peristalsis contraction to move food bolus
- Line blood vessels, mainly arteries and arterioles whicih undergo vasoconstriction and vasodilation to control blood flow
- veins and venules also contain smooth muscle but less than arteries and arterioles
- Also in bladder, uterus
Smooth muscle
Under involuntary control (autonomic branch)
- sympathetic and parasympathetic
Nonstriated due to lack of sarcomeres, instead contains more loosely organized fibers of myosin and actin that contract
Uninucleate, one nucleus per cell
Cardiac muscle
Makes up the heart
- hybrid between skeletal and smooth muscle
- Uninucleate most of the time
- Autonomic: myogenic activity
- Striated due to sarcomeres
Contract synchronously with the help of intercalated discs: gap junctions between cardiomyocytes with ion channels b/w adjacent cells
- flow of ions allows simultaneous contraction
How does the heart Contract synchronously
with the help of intercalated discs: contains gap junctions between cardiomyocytes with ion channels b/w adjacent cells
- flow of ions allows simultaneous contraction
Cardiac muscle myogenic activity
Heart contains region known as sinoatrial (SA) node thats populated with pacemaker cells
- ontract at own rhythm at about 60-100 bpm
SA node transmits signals to the rest of the heart, can be modified by inputs from parasympathetic and sympathetic NS
Muscle generates force when
Its individual fibers contract (shorten)
Muscle contraction
Sliding Filament Theory
Sarcomere: repeating unit in striated muscle cells containing myosin and actin
- smooth muscle doesn’t contain sarcomeres but contains myosin and actin fibers which can contract
Sliding Filament Theory: Myosin and actin fibers bind and tug at each other to shorten length of sarcomere
To cause muscle contraction, actin slides over myosin thick filaments at the center of the sarcomere
- Actin encroaches on H zone (only myosin) and overlaps with it, H-zone effectively shrinks
Sacromeres anatomy and Sliding Filament Theory
Sliding Filament Theory: Myosin and actin fibers bind and tug at each other to shorten length of sarcomere
- Actin (thin) filaments are anchored to Z-lines: form boundaries of the sacromere
M-line: middle of the sacromere
H-zone: spans length of sacromere that only contains thick myosin filaments with no overlap from actin (in middle)
I-band: spans region contains only thin actin filaments (near Z line)
A-band: spans entire length of myosin filament
Only region that contains its length during muscle contraction
A-band: spans entire length of myosin filament
4 stages of contraction:
Cross-bridge cycle
Myosin thick filaments have specialized head domain which is initially bound to actin filament
- To initiate contraction, ATP molecule has to bind to myosin head releasing actin
- ATP hydrolyzes releasing ADP and inorganic phosphate (Pi), which releases energy and moves myosin head further from actin
- Myosin binds actin at a new position upstream and generates force which pulls actin over myosin, closer to center of sarcomere
* shortens sarcomere = Power stroke - Bound myosin head awaits ATP molecule to begin next cyle
Regulation of muscle contraction
Calcium
Myosin binding site in actin are by default blocked by the protein tropomyosin
- Only when calcium is present in cell, it can bind the protein troponin which moves tropomysin out of actin’s way so it can interact with myosin
Two ingredients required for muscle contraction
ATP to move myosin heads and calcium to move tropomyosin out of the way
What decides when muscles contract
Neuromuscular Contraction
- Motor neurons interface with skeletal muscles at the neuromuscular junction (NMJ)
To stimulate muscle contraction, motor neuron initiates action potential which causes neurotransmitters to release into NMJ
- *** ALWAYS Acetlycholine (ACh)
Triggers influx of sodium into muscle cell, depolarization at cell membrane
Motor unit
One neuron innervates a group of muscles
Nicotinic receptors
Acetylcholine receptors at muscle cell membrane (sarcolemma)
Once muscle cell sarcolemma experiences depolarization from acteylocholine..
Action potential travels down sarcolemma to transverse (T) tubules that penetrate into the cell to the sarcoplasmic reticulum (smooth ER in myocytes)
- triggers opening of calcium channels causing sarcoplasmic reticulum to release stores of calcium ions
- intracellular calcium conc is usually very low
Calcium causes tropomyocin to dissociate from myocin binding sites on actin, allowing them to interact
For muscles to relax…
Any contraction inducing stimuli must be removed
- Enzyme acetylcholinesterase breaks down acetylcholine neurotransmitter in NMJ
In absence of further stimulation, sarcolemma repolarizes, calcium returned to sarcoplasmic reticulum, muscle relaxes
Twitch
Summation
Tetanus
One isolated muscle contraction
Multiple action potentials lead to stronger muscle contraction
Longer lasting, sustained contraction
If insufficient oxygen is present, muscles…
Switch to glycolysis and lactic acid fermentation
Too much anaerobic exercise causes
Lactic acid buildup
- Most is converted back to pyruvate
Rigor mortis
Body’s muscles become quite rigid after death due to no ATP to bind to myosin
Largest organ in the human body
Skin
Integument
Skin
Integumentary system components and general function
Skin, hair, nails, sweat glands, sebaceous glands
- physical barrier, thermoregulation, immune defense, sensation
Outermost layer of the skin
epidermis, which can itself be divided into 5 layers
Epidermis is primarily composed of
Also contains
Dead keratinocytes (skin cells packed with fibrous protein keratin)
- as new cells created by mitosis, older ones are pushed outwards further from the capillaries
- deprived of oxygen and die
- Produce keratin as a SEALANT, make epithelium impermeable to water
- similar to hair
Also contains lipid matrix, keratinocyte stem cells, melanocytes (produce melanin), Langerhan cells (antigen presenting dendritic cells, monitor for invading pathogens), Merkel cells (mechanoreceptors that sense touch, more dense in sensitive parts of body)
Melanin synthesis is upregulated in response to
Differences in skin color due to
Ultraviolet damage
Differences due to activity of melanocytes and not how many there are
Layer under the epidermis
Dermis, dense connective tissue, blood and lymphatic vessels, hair follicles, sweat glands
Dermis mechanoreceptors
Ruffini endings (sense stretching)
Pacinian corpuscles (vibration/pressure)
Meissner corpuscles (sensitive touch)
Hypodermis (also called?)
Contains
Below the dermis (which is below the epidermis)
- also called subcutaneous layer
Contains adipocytes (fat cells) (structural support and insulation)
Also contains macrophages, patrol area for pathogens
Thermoregulation - when we’re cold
piloerection
When we’re cold, arrector pili muscles surrounding hair follicles contract and they become vertical
- traps warm air close to skin, creates goosebumps
Arterioles near the surface of the skin can vasoconstrict under sympathetic control, diverting blood from skin to other locations
Thermoregulation - when we’re hot
Sweat glands secrete water and other minerals onto skin surface and cool us down through evaporative cooling
- water has high heat capacity, water can absorb a lot of heat energy and experience small temp increase in response
Vasodilation allows more blood to reach skin surface and cool us down
Thermoregulation is controlled by
Hypothalamus
Mirror
Convex vs. Concave
Any substance from which light rays reflect, without significant absorption or refraction
Concave curves towards the observer, convex curves away from the observer
Plane mirrors don’t curve
When light rays emanating from an object reflect from a mirror…
We can see them as an image
Concave mirrors form __ images
Convex mirrors form __ images
Real, convergence of physically real light waves
Virtual
Focal point
Where incident rays converge
f = r/2
- concave, meet on same side as object
- convex, meet on opposite side
plane mirrors
Thin lens equation
Focal point and radius can be thought of as infinite
- O = distance of object, I = distance of image
1/O + 1/i = 1/f
Magnification equation
Negative vs. positive values?
m = -i/o
Image appears larger when absolute value is >1
Image is inverted if value is negative = real
- Positive: image is upright, its virtual (looking in a mirror)
Tracing ray diagrams for mirrors
One ray is parallel from object to mirror, then bounces off through focal point
Second ray is from top of object straight through focal point then reflects off mirror parallel to the first ray
Image is where these two rays intersect
- **Use thin lens equation
For concave mirrors, if image is at focal point
No image is formed, i = infinity
Lenses are different form mirrors in that…
Which lens cause light to converge, which to diverge?
Light passes through them almost completely, bending or refracting
- *** Opposite of mirrors: convex cause light to converge
- Concave cause light to diverge
Lenses
positive image value for lenses
negative image value
Real image is opposite and inverted
Negative = virtual image on same side as object
Power of a lens, P
Diopter?
Reciprocal of the focal length in meters
P = 1/f
Shorter the focal length, the greater the power
- lens with a small focal length bends light considerably
Diopter = inverse meters
Spherical abberation
Rays don’t meet up perfectly when refracted through lens or reflected by mirror
- light rays that hit close to the center of the lens focus farther away compared to the edges
Systems with multiple lenses
mtotal =
Image generated by one lens serves as the object as the next lens, which in turn generates a second image
mtotal = m1 x m2…
The human eye
Myopia
- Light is refracted by cornea, which refracts to a fixed focal length
- The lens of the eye is deeper and more flexible, can modify image to focus on retina
myopia: nearsighted, lens refracts light too much making light converge in front of the retina
- corrected with diverging lens that spreads out light rays to hit retina
hyperopia: farsightedness, light converges behind the retina
- corrected with converging lens
Two ways body stores energy for future use:
Adipose tissue and glycogen stores
- glycogen is usually the go to when blood glucose gets low
What is glycogen
Center of glycogen polymer contains…
Glucose molecules in each chain are linked by
Branched polymer of glucose, thousands of glucose molecules strung together
- Center contains protein called glycogenin: attachment point for many individual chains of glucose which are themselves branched
Glucose molecules are linked by alpha 1,4 bonds
Glycogen is stored in
liver and skeletal muscle
- liver is where gluconeogenesis and glycogenolysis occur
- skeletal muscles need stores for energy
Blood glucose is maintained by…
The liver through gluconeogenesis (glucose from scratch) and liberating glucose from stores = glycogenolysis
Glycogenesis - when does it occur in liver, when in skeletal muscle cells?
In the liver when extra glucose in the blood
In skeletal muscle cells it occurs after physical activity/exertion
\
Glycogenesis steps
- Begins with glucose 6-phosphate (G6P) converted to G1P using enzyme phosphoglucomutase
- G1P converted to UDP-glucose (type of nucleotide, like GTP and ATP) which is derived from UTP
-
Glycogen synthase breaks UDP off and creates alpha 1,4 bond between new glucose and existing chain
* **glycogen synthase CAN’T create new branches
Glucose 6 phosphate (G6P) is involved in
Glycolysis/gluconeogenesis (intermediate)
Glyogenesis
What creates new glycogen branches
Glycogen Branching Enzyme
Creates alpha 1,6 bonds
How does glycogen molecule begin?
Glycogenin adds first few glucose molecules itself, starting points for chains created by glycogen synthase and glycogen branching enzyme
Glycogenolysis steps
Breakdown of glycogen for energy
- Breakdown of glycogen into glucose 1-phosphate by glycogen phosphorylase
- phosphorylysis: ***adds PHOSPHATE GROUP to glucose at the end of chain replacing the alpha 1,4 bond
- NEEDS glycogen debranching enzyme to break alpha 1,6 bond at the end of chains
- G1P into G6P by phosphoglucomutase
G6P can then enter glycolysis or gluconeogenesis depending on bodily needs
Glucose 1-phosphate G1P is specific to what pathways?
Glycogenolysis, glycogenesis
How is glycogen breakdown regulated differently in liver and skeletal cells?
Whats the main enzyme?
Glycogen phosphorylase is regulated by epinephrine hormone in skeletal cells
- when epinephrine binds to receptors on skeletal cells, kicks off signaling cascade which activated glycogen phosphorylase
- releases G1P
In the liver, glucagon activates glycogen phosphorylase to raise blood glucose when you haven’t eaten in a while
Hunger hormone
Glucagon, stimulates breakdown of glycogen for glucose when we haven’t eaten in a while to raise blood glucose
What hormone inhibits glycogenolysis
Insulin in liver cells, promotes satiety (fullness)
How is glycogen phosphorylase allosterically inhibited in liver vs. muscle cells
In muscle cells, calcium ions upregulate glycogen phosphorylase
- if muscle cells actively contracting, need glucose
- AMP is a sign of low energy, also upregulated glycogenolysis
In liver cells, glucose allosterically inhibits glycogen phosphorylase
Main enzyme for glucogenesis regulation?
How is this enzyme regulated? differently in liver vs. skeletal cells?
Glycogen synthase (responsible for lengthening glycogen branches)
- Insulin upregulated glycogen synthase, causing cells to make more glycogen
Insulin is produced when blood glucose is high, main job is to get glucose into the cells
- Inhibits its inhibitor
What is the Pentose Phosphate Pathway’s purpose
Basic equation?
Anabolic pathway that makes raw materials for biosynthesis
- bigger molecules out of smaller ones
NADP+ into NADPH and produces sugar ribose 5-phosphate
Pentose phosphate products:
NADPH is
Ribose 5-phophate is
NADPH is a powerful antioxidant agent used as reducing agent in nucleic acid and lipid synthesis
Ribose 5-phosphate is a sugar component of nucleotides
Two phases of pentose phosphate pathway:
Oxidative phase
1. Oxidative phase
-
G6P shunted away from glycolysis when cell wants to build biomolecules
- converted into 6-phosphogluconolactone by G6P dehydrogenase
- **Rate limiting, produces one NADPH
- converted into 6-phosphogluconolactone by G6P dehydrogenase
- Converted to 6-phosphogluconate and then cleaved into Ribulose 5-phosphate
- Another NADPH produced
- This can easily be converted to Ribose 5-phosphate
