Lecture Exam 1 SLO's Flashcards
Defining characteristics of nervous tissue.
~ transmit info via electrical signals; branches send and receive signals
~communication and control
~ sensory, motor and integration
~ excitable- respond to electrical signals
-neuroglia~ support cells, nonexcitable, more neuroglia than neurons
Defining characteristics of muscle tissue.
~ skeletal, smooth, cardiac
~ always PULL never push
~movement, thermoregulation, extensibility, elasticity, contractility (shortening), excitability
Defining characteristics of epithelial tissue.
~ sheet like arrangement with a basement membrane of thin CT
~ covers/lines, simple vs stratified (name based on most apical layer), squamous, cuboidal, columnar, high cellularity
~forms glands
Exocrine vs endocrine glands
Exocrine~ secretory epithelial cells responsible for creating and releasing materials, duct forms walls of gland itself where product will be released from, releases product onto FREE SURFACE
Endocrine~ releases product INTO BLOODSTREAM, secretory cells release chemical messengers (hormones) into blood
Defining characteristics of connective tissue.
~most abundant and diverse
~ support, lots of ECM
~bone, blood, CT proper
~ joints
Describe the distribution of water in the human body
~Total body water divided into intracellular fluid (ICF) and extracellular fluid (ECF)
~ ECF divided into plasma and interstitial fluid (ISF)
~TBW makes up majority of body, followed by ICF, then ECF, then ISF and plasma
Define the different body fluid compartments.
~ fluid compartments separated by semipermeable membranes
~
Define homeostasis.
~ maintenance of constant conditions in the internal environment (ECF) such as composition of ECF, temperature of ECF, and volume of ECF.
Explain the significance of homeostasis to the function of the human body.
~ all organ systems EXCEPT reproductive function to maintain homeostasis
~ prevents irregularities in the body even in the presence of foreign conditions such as when working out, body temp rises, begin to sweat to cool down
Describe the role of negative feedback in homeostasis and list at least one example of its function in the human body
~ corrective action, return to a normal state, more common
~ change in regulated variable (set point), integrating center, signals to effectors, effectors, response
~never specific set point but a normal homeostatic range
~ex: change in blood glucose at set point, integrating center at beta cells of pancreas signals effectors by releasing insulin, cells throughout the body (effectors) respond by lowering blood glucose
List an example of a positive feedback mechanism in the human body
~ exacerbates, less common
~ex: pituitary gland secretes LH, increases estrogen secretion from ovaries, back to pituitary gland, releases more LH and increases estrogen until terminal signal- ovum is released.
Distinguish between the terms internal and external environment. Provide examples
~one layer of epithelial tissue separates internal and external environments; often overlap between internal and external
Internal~ never exposed to external environment, operates solely internally; ex: cardiovascular, nervous, muscular
External~ exposed to external environment outside of body; ex: digestive, urinary, respiratory
List the general characteristics of carbohydrates and their general function in cells
~ composed of monosaccharides, disaccharides, and polysaccharides
~ polar molecules, H2O soluble
~provide energy to cells
List the general characteristics of lipids and their general function in cells.
~ non polar, insoluble in H2O, some have a polar functional group with polar and nonpolar ends making it amphipathic
~ triglycerides, phospholipids, steroids, eicosanoids
~energy storage
List the general characteristics of proteins and their general function in cells
~ amino acids, central carbon, carboxyl, amino group and R group
~ primary structure- amino acid sequence attached by peptide bonds
~secondary structure- twisting and bending of amino acid sequence, alpha helix (spiral) and beta pleated sheet (folds)
~tertiary structure- secondary structure present but jumbled, some proteins are complete here
~quaternary structure- larger proteins composed of multiple individual proteins in tertiary structure
~fibrous, globular, mixed shapes
List the general characteristics of nucleotides and their general function in cells
~ energy transference, intracellular signaling (ring structure from P grp curving and bonding back to C ring) genetic information (C ring sugar, P grp, pyrimidine or purine base)
Hydroxyl group characteristics on biomolecules
-OH
~ polar; hydrophilic
Sulfhydryl group characteristics on biomolecules
-SH
~ polar; hydrophilic
Phosphate group characteristics on biomolecules
-HPO4
~polar; hydrophilic
Carboxyl group characteristics on biomolecules
-COOH
~ acid
Amino group characteristics on biomolecules
-NH2
~ base
List the three main parts of all cells in the human body
~ plasma membrane, cytoplasm, nucleus
Describe the structure and major functions of the plasma membrane
~ phospholipids- regulation of diffusion of materials
~ cholesterol- steroid lipid, amphipathic b/s of hydroxyl, only in animal cells, provides rigidity
~ peripheral membrane proteins- not embedded
~ integral proteins- partially/completely embedded
~ transmembrane proteins- spans width of membrane, receptor or channel
~ carbohydrate chains- attached to protein or lipid, forms glycoproteins or glycolipids for adherence or cellular identification
Describe the structure and major functions of the nucleus
~ nucleolus- responsible for synthesizing rRNA for ribosomes
~ chromatin- genetic material
~ double membrane
~ nuclear pores- allow material to enter/exit
~ control center
Describe the structure and major functions of the cytoplasm
~ cytosol and organelles
~ mostly made of water, ionic composition different from ECF, has inclusions and secretory vesicles
~ transport materials in/out cell
Describe the structure and major functions of the rough endoplasmic reticulum
~ synthesize proteins
~ has ribosomes on surface hence ‘rough’
~ flat cisternae
~continuous with nuclear envelope
Describe the structure and major functions of the smooth endoplasmic reticulum
~ extension of rough ER, loses the ribosomes on surface
~ produces steroids and triglycerides
~ tubular cisternae
Describe the structure and major functions of the golgi apparatus
~ sorting center, post office
~ lipids and proteins transferred from ER
~cis face receives, travels thru cisternae and is shipped from trans face
Describe the structure and major functions of the mitochondrion
~ double membrane with intermembrane space
~ cristae- folds of inner membrane to increase SA and pack in more proteins
~ matrix- space inside inner membrane
Describe the structure and major functions of the lysosome
~ degradation organelle
~ fuses with damaged organelle, releases enzymes, breaks down material and recycles parts into cytosol (autolysis)
~endosome- vesicle bringing material into cell and fuses with lysosome
Describe the structure and major functions of the peroxisome
~ detoxification, neutralize free radicals
~found predominantly in liver
Describe the structure and major functions of ribsosomes
~ 2 subunits (large and small subunit- tertiary structure), full ribosome- quaternary structure and rRNA helps form
Describe the structure and major functions of the cytoskeleton
~ cytoskeletal filaments- proteins; ensures nothing falls through cell due to gravity
~microfilaments- smallest, actin, inside the microvilli to stand them up
~microvilli- extensions of membrane
~ intermediate filaments- bigger, woven structure, myosin and keratin
~ microtubules- largest, hollow coil, in cilia and flagella
Describe tight junctions
~ fuses with cell walls, impenetrable between cells
Describe desmosomes
~ anchor cells together to resist pulling forces, zipper, does not prevent movement
Describe gap junctions
~ tunnels, joining doors between hotel rooms
~ electrical and metabolic coupling
Differentiate between direct and indirect intercellular communication
Direct~ gap junctions (coupling), interior to interior
Indirect~ chemical messengers used; released by one cell and received by another
Describe transcription in detail
~ RNA synthesized from sense strand of DNA (in nucleus)
~ RNA polymerase creates mRNA strand:
1. promoter sequence says start here
2. RNA polymerase binds and uncoils DNA and reads base nucleotides along one strand
3. brings complementary base pair for mRNA and moves segment by segment (elongation)
4. forms pre-mRNA which copies word for word
~post transcriptional modifications (edit pre-m RNA):
1. reads exons (coding regions) and splices out introns (regulatory function/noncoding)
2. adds CAP (helmet) and poly-A tail (lots of adenines) for mRNA stability to tail to protect coding instructions from degrading enzymes
3. mRNA exits into cytosol
Describe translation in detail
~ polypeptides synthesized using RNA codons as template for assembly of amino acids (in cytosol)
1. start codon begins reading
2. small ribosomal subunit binds to start codon
3. tRNA (anticodon) complementary to codon, codes for amino acid
4. large ribosomal subunit comes in, feeds mRNA through the ribosome, another tRNA codes for amino acids
5. Peptide bonds form between amino acids
6. tRNA dissociates and finds another amino acid because Met attached and repeats
7. polypeptide is formed, elongated and released into the rough ER lumen and moves to the smooth ER then to golgi via a vesicle
8. golgi completes post translational modifications and packages into a vesicle to be released from the golgi
9. destination: exocytosis, membrane, cytosol
Describe the role of DNA in protein synthesis
~ allows nucleus of a cell to control/regulate cell activity by coding for cellular proteins and controls cell activity outside of the nucleus by RNA which exits thru nuclear pores
~ instructions for protein synthesis
Describe the role of genes in protein synthesis
~ segment of DNA with very specific order of linked nucleotides that codes for a specific protein
~ double strand with gene is the template strand of DNA transcribed into mRNA by complementary base pairing
Describe the role of codons in protein synthesis
~ complementary base pairs to mRNA segments
~ reads mRNA, anticodon attaches (tRNA) to code for amino acids
Describe the role of mRNA in protein synthesis
~ messenger RNA
~ complementary to template strand of DNA
~ read by anticodons, forms codons
Describe the role of tRNA in protein synthesis
~ complementary to mRNA codons
~ attached to anticodons which code for amino acid sequence
~ dissociates and finds another codon to make amino acids
Describe the role of ribosomes in protein synthesis
~ small subunit binds to start codon and reads, large subunit comes in and mRNA feeds through the ribosome and another tRNA codes for amino acid
Describe the role of leader sequence in protein synthesis
~ translated and signal recognition protein binds to leader sequence and rough ER, causing attachment of ribosome and elongation and trapping of polypeptide in lumen of rough ER
Describe the role of golgi apparatus in protein synthesis
~ cis face receives transport vesicles of polypeptide buds from smooth ER
~released from trans face by destination of cytosol, membrane or exocytosis
Define metabolism
~ sum total of all chemical reactions in cells
Differentiate between catabolic and anabolic reactions
Catabolic~ breakdown of larger molecules into smaller products
Anabolic~ produce larger molecules from smaller reactants
Describe what occurs in hydrolysis
~ splitting with water
~ larger molecule broken down by water into smaller products; catabolic
Describe what occurs in condensation
~ form water
~ smaller reactants combine and form water as a byproduct of; anabolic
Describe what occurs in phosphorylation
~ adding a phosphate group,
Describe what occurs in dephosphorylation
~removal of a phosphate group
Describe what occurs in oxidation
~ removal of electrons, forms ion product
Describe what occurs in reduction
~ accept/gain electrons, electrons combine with ions to form uncharged atoms
Describe the general mechanism of enzyme action.
~ enzymes increase reaction rates
~biological catalysts, substrate specific, do not change the nature of the reaction or the final product, enzymes themselves are not changed by the reaction.
What are the factors that affect enzyme catalyzed reactions?
~concentrations of substrate and enzyme
~temperature
~pH
~cofactors and coenzymes
~ affinity
How does saturation influence rate of enzyme reactions?
~ substrate concentration and amount of enzymes
~ higher concentration results in a faster reaction rate
~ higher concentrations of enzymes reach the maximum point of saturation later than low [E]
How does temperature affect rate of enzyme reactions?
~ body temperature is tightly regulated so changes are rarely significant
~ high body temperature causes protein denaturation
How does pH influence enzyme reactions rate?
~ increasing the acidity decreases enzyme activity by causing structural changes as well as altering the active site
~ there is no common optimal pH for an enzyme; depends on enzyme and acidity
How do cofactors influence enzyme reaction rate?
~many enzymes require a cofactor
~derived from vitamins and minerals
~ functions to lock the reacting substance into its active site
~ without the cofactor, the reaction cannot take place
-vitamin deficiency diseases
How do coenzymes influence enzyme reaction rate?
~ derivatives of cofactors
~ act as taxis and ubers to carry chemical groups to reactions
~unchanged by reactions and can be reused
How does affinity influence enzyme reaction rates?
~ do substrates and enzymes like each other?
~ with a higher affinity, reaction is more efficient
~ lower affinity levels off later than a higher affinity
Define energy.
~ capacity to do work
What is kinetic energy?
~ matter in motion; particles move and vibrate randomly at any temperature above absolute 0
What is potential energy?
~ energy stored in matter; has potential to become kinetic energy
~ exists in bonds between atoms because the bonds can be broken to release energy
What is the first law of thermodynamics?
~energy can neither be created nor destroyed, just converted from one type to the other
What is the second law of thermodynamics?
~natural processes tend to proceed in the direction that spreads energy
ex: diffusion
Describe the energy change in exergonic reactions
~ energy change is negative
~ proceeds spontaneously
~ Reactants contain more energy than products
~energy is released
~ catabolic rxn
-draw the graph*
Describe the energy change in endergonic reactions
~ energy change is positive
~does NOT occur spontaneously
~ requires energy to be added
~ reactants have less energy than products
~ anabolic rxn
-draw graph*
Define exergonic-endergonic coupling
~ energy released from catabolic reactions is used to drive anabolic reactions
What is a calorie?
~ amount of energy/heat required to raise the temperature of 1 gram of water by 1 degree celsius
Define equilibrium in a chemical reaction
~ reactants are being converted to products at the same rate products are converted to reactants
~ change in energy=0
~ does not necessarily mean concentrations are equal
~ if the energy difference is large between reactants and products then the concentration difference will also be large at equilibrium
What is the Law of Mass Action?
~ an increase in reactant concentration relative to product concentration tends to push a reaction FORWARD
~ an increase in product concentration relative to reactant concentration tends to push a reaction in REVERSE
~ equilibrium constant (K)= [P] / [R]
Define the transition state of an exergonic reaction.
~ energy from the collision of reactants required to overcome the activation energy barrier.
Describe allosteric regulation. What shape is an allosteric curve?
~ allosteric enzymes have an active site and a regulatory site where a modulator binds to the regulatory site and the substrate binds to the active site, changing enzymatic activity
~sigmoidal curve
Differentiate between an allosteric activator and an allosteric inhibitor
Activator~ increase enzyme activity, leftward shift
Inhibitor~ reduce activity, rightward shift
graphs
Describe covalent regulation.
~ phosphorylation/dephosphorylation- adding or removing a phosphate group by kinases and phosphatases respectively
~ chemical group is attached to enzyme by kinase action and removed by phosphatase to alter active site
Describe feedback inhibition
~ reactants cam signal enzymes to stop catalyzing
~ end product inhibition is when the reaction stops working and the final product is made
Describe the role of ATP in energy metabolism.
~energy released in exergonic reactions must be captured to do work in the cell and synthesize ATP
~ ADP receives a P group and forms ATP with H2O as a byproduct
~condensation, phosphorylation and endergonic reactions take place
Describe ATP synthesis: substrate level phosphorylation
~ P group transferred from metabolic intermediate, x, to ADP to form ATP
~anaerobic
~ x-P + ADP –> x + ATP
Describe ATP synthesis: oxidative phosphorylation
~ ADP binds with a free, inorganic P to form ATP
~ aerobic; requires O2 and ETC
~ ADP + P –> ATP
Describe ATP breakdown
~ releasing energy
~ ATP + H2O –> ADP + P + energy
~ ATP hydrolysis; high energy P bonds are broken
~ when cells need energy to perform work, they must hydrolyze previously formed ATP
Describe in general terms the events and byproducts produced by glycolysis
~completed in the cytosol
~ Glucose + 2NAD+(coenzyme) + 2ADP + 2P –> 2pyruvate + 2NADH + 2H+ + 2ATP
~ 10 enzyme catalyzed reactions
~ For each molecule of glucose:
-2 pyruvate molecules produced
- 2 ATP molecules consumed
- 4 ATP molecules produced
- 2 NAD+ molecules reduced to 2 NADH
~anaerobic
~ no CO2 produced
~ hexokinase used to catalyze phosphorylation reaction by adding P to glucose
-ATP’s P added to glucose leaving ADP
~ glucose splits and reaction occurs twice
~reduced NADH2 goes to oxidative phosphorylation
Describe in general terms the events and byproducts produced by the linking step
~ pyruvate enters the mitochondrial matrix and gets converted to acetyl coA
~ pyruvate + CoA + NAD+ –> CoA + CO2 + NADH + H+
~ reaction occurs two times per glucose molecule
so 2CO2 and 2NADH2 produced
Describe in general terms the events and byproducts produced by the krebs cycle
~ glucose –> 2pyruvate –> 2acetylCoA
-each acetyl CoA is one full cycle
~NAD+ reduced to NADH 3 times
~ CO2 waste produced
~ FAD reduced to FADH2
~ substrate level phosphorylation used (2ATP from glycolysis) to make ATP by ADP stealing P from GTP-> GDP
~reduce as many coenzymes as possible for oxidative phosphorylation and more ATP synthesis
Describe in general terms the events and byproducts produced by oxidative phosphorylation
ETC:
- only electrons are transported
- only difference between NADH (at beginning) and FADH2 (after pump 1) is where on the ETC they drop off electrons
-O2 is final electron acceptor, forms H2O
-ATP used immediately by complexes of ETC to transport H+
Chemiosmotic Coupling:
- movement of H ions into the intermembrane space
- NADH drops off electrons at the beginning of the ETC into complex 1 and initiates active transport of H+ from matrix into intermembrane space
- electrons reach complex 3 and do the same with the H+, same in complex 4
-causes buildup of H+ in intermembrane space, following diffusion, ATP synthase transports the ions back into the matrix whilst rotating and generating 1 ATP per 4 H+
-complexes of ETC made up of different proteins in quaternary structure
-movement of H+ coupled with electrons
How many ATP produced in each pump and coenzyme?
1st pump (1)~ 4H+, 1 ATP
2nd pump (3)~ 4H+, 1 ATP
3rd pump (4)~ 2H+, 0.5 ATP
-NADH pumps all three~ 10H+, 2.5 ATP
-FADH2 pumps after 1st complex, only 3 and 4~ 6H+, 1.5 ATP
TOTAL~ 32 ATP/glucose molecule
Describe in general terms how the body is able to obtain energy from the breakdown of glucose and pyruvate
~ if metabolic demand outweighs O2 delivery, the ETC will slow down and stop, leaving little to no NAD+, which is necessary for glycolysis
~ electrons stall, no H+ movement, without glycolysis there is not enough ATP-generating capacity for a cell to survive, no NAD to recycle back to glycolysis
~ SO convert pyruvate to lactic acid and continue surviving off of continual production of 2 ATP until O2 becomes available
Describe in general terms how the body is able to obtain energy from the breakdown of fats
~triglyceride broken into glycerol and fatty acids (lypolysis)
Describe in general terms how the body is able to obtain energy from the breakdown of proteins
~ proteins broken into amino acids (proteolysis)
Where is hexokinase found vs glucose 6 phosphatase
~ present in most cells for glycolysis, adds P to glucose for glycolysis
~ only present in liver cells so glycogen can be converted to glucose which can be shipped out into the blood, removes a P group
