Biology Flashcards
What are the three roles of Peroxisomes?
- Contain hydrogen peroxide to break down long chain fatty acids via Beta-oxidation
- Involved in phospholipid synthesis
- Participate in pentose phosphate pathway.
What are microfilaments made of and what are the three things they do?
- Composed of actin.
- Provide structural integrity and cause muscle contractions through myosin.
- Help form cleavage farrow during cytokinesis.
What are microtubles made of and what are the two things they do?
- Composed of tubulin.
- Create pathway for motor proteins like kinesin and dynein.
- Contribute to structure of cilia and flagella.
What are the three roles of intermediate filaments?
- Involved in cell-cell adhesion
- cytoskeleton integrity
- Anchor organelles
(Keratin and desmin)
What is transduction?
transfer of genetic material from one bacterium to another via a bacteriaphage vector
What is a plasmid that can integrate into the genome?
episomes
What are the four stages of bacterial growth?
Lag phase: adapt to new conditions
Exponential phase: growth increases
Stationary phase: as resources reduce, growth reduces
Death phase: resource depletion
What does it mean for a single stranded RNA virus to be positive sense and negative sense?
Positive sense: can be translated by the host cell
Negative sense: requires a complementary strand to be synthesized by RNA replicase
What are the two life cycles of Bacteriophages?
Lytic cycle: produces new viriones until cell lysises. Bacteria is virulent
Lysogenic cycle: virus integrates into the host genome as a pro-virus or prophage and then reproduce with cell
What are the three types of nucleic acids that can form a viral genome?
Single-stranded RNA
Single-stranded DNA
Double-stranded DNA
What are the three similarities between Archaea and bacteria?
- The contain a nucleus or membrane bound organelles
- Contain a circular chromosome
- Divide by binary fission or budding
What are the three similarities between Archaea and Eukaryotes?
- They start translation with methionine
- Contain similar RNA polymerases
- Contain DNA associated with histones
How does a retrovirus infect host cell?
Has a single stranded RNA that undergoes reverse transcriptase to form a double stranded DNA. This DNA enters host genome and replicates.
Where and what are the two checkpoints in the cell cycle?
- G1/S: determine if the conditions are good enough for synthesis (restriction point)
- G2/M: cell is ensuring that the cell has achieved an adequate size and the organelles are replicated
What protein plays a role in the G1/S and G2/M checkpoints
p53
What two molecule are responsible for the cell cycle? How?
cyclins and CDKs
-form a CDK-cyclin complex to phosphorylate transcription factors
What is one notable gene on the Y chromosome? Function?
SRY, which encodes for a transcription factor that initiates testis differentiation (male gonad formation)
What are the two functional components of the testes?
- Seminiferous tubules
- Interstitial cells of Leydig
What is the primary function of sertoli cells? Where are they located?
Located in seminiferous tubules and nourish the sperm produced there
What is the primary function of Leydig cells?
Secrete testosteron and other androgens
What is the midpiece of a sperm and primary function?
Filled with mitochondria and generate ATP to swim
What is the 6 step pathway for sperm
Seminiferous tubules
Epididymis
Vas deferens
Ejaculatory duct
Urethra
Penis
What are the three structures that make seminal fluid? What is main contribution from each?
- Seminal vesicles: contribute fructose/give alkaline properties
- Prostate gland: make fluid alkaline
- Bulbourethral: produce clear fluid to clean out urine and lubricants in urethra
What are the five stages of spermatogenesis?
What structure on the head of the sperm is necesary to penetrate ovum? What makes this structure?
Cap known as acrosome (made by golgi)
Where are eggs ovulated into before going into the fallopian tube?
Peritoneal sac
What are the two layers that surround the oocyte? Two descriptions for each?
- Zona Pellucida: protect/contain compounds for sperm binding
- Corona Radiata: outside the zona pellucida/ adhere to the oocyte during ovulation
What hormone does the hypothalamus restrict before puberty? What does this hormone do?
GnRH, which triggers the anterior pituitary gland to synthesize and release FSH and LH
What role do FSH and LH play in male sexual development?
- FSH stimulatr sertoli cells and trigger sperm maturation
- LH causes interstitial cells to produce testosteron
Which structure secretes progesterone?
corpus luteum
What is one difference in the role between estrogen and progesterone
- estrogen is involved in the intial thickening of the endometrium
- Progesterone is involved in the maintenance and development of endometrium
What are the four stages of a menstrual cycle?
- Follicular Phase
- Ovulation
- Luteal Phase
- Menstruation
What are the five stages of Follicular Phase?
- shed uterine lining
- GnRH increases because estrogen/progesterone decreased
- Increase secretion of FSH and LH
- Follicles form and produce estrogen
- Endometrial lining becomes ascularization and glandularized
What is the main event that happens during ovulation and how is it instigated?
Spike in Estrogen causes spike in LH/FSH, egg is released from follicle into peritoneal cavity
What are the two main characteristics of luteal phase?
- Spike in LH causes the ruptured follicle to form the corpus luteum
- Increase in progesteron causes negative feedback of LH, GnRH, FSH so another eggs is not ovulated
What are the two primary characteristic of menstruation?
- No implantation, decrease in progesterone and uterine lining sheds
- reduction in FSH, LH, estrogen as well
Why is it important for a blastocyst to secrete hCG during the first trimester?
- It is an analog to LH and maintains corpus luteum, maintaining uterine lining.
- By second trimester, the placenta can secrete progesterone and estrogen, do not need corpus luteum.
What are two key features of menopause?
- less sensitive to FSH and LH
- Estrogen/progesterone levels drops and no negative feedback on FSH and LH
What stage of meiosis is the egg in when it is being ovulated, birth to before ovulation, when a sperm penetrates?
- Ovulation: complete meiosis I and in metaphase II (secondary oocyte)
- birth to before ovulation: prophase I (primary oocyte)
- sperm penetrates: complete meoisis II (mature ovum)
When do kinetochores initially connect to spindle fibers?
prophase
Where does fertilization occur?
Ampulla: widest part of the fallopian tube
What does the first sperm to come into contact with the seconary oocyte form? Function?
acrosomal apparatus so the sperm’s pronucleus can enter the egg
What is the reaction after the sperm penetrates and are the two events it causes?
Causes the release of Ca+
- depolarization creates a fertilization membrane and prevent fertilization of ovum from mulitiple sperm
- Increase the metabolic rate of newly formed zygote
What are the five stages of development from Zygote to gastrula?Which one has the highest nuclear to cytoplasm ratio?
- Zygote
- cell embryo
- morula
- blatula (hollow ball of cells with a fluid filled inner cavity called blastocoel)–> implantation
- gastrula
What are the two subgroups of cells that makeup the blastocyst?
- Trophoblast cells: surround the bastocell and give rise to the chorion which surrounds the amnion (extraembyronic membrane that developes into the placenta) and later the placenta
- Inner cell mass: protrudes into the blastocoel and gives rise to the organism itself
What forms the chrionic villia and what do they do?
- Trophoblast cells
- finger-like projections that penetrate the endometrium
Besides the trophoblasts, what are the other two extraembryonic membranes?
- allantois: involved in early fluid exchange between embryo and yolk sac. Umbilical cord is formed from remnants of the yolk sac and allantois
- amnion: surrounds the allantois and is a thin, tough membrane filled with amniotic fluid/ is a shock absorber from maternal movement
What are the four main steps of neurulation?
- Notocord induces a group of ectodermal cells to slide inward to dome neural folds around the neural groove
- Neural folds grow towards each other and fuse into neural tube
- At the tip of each neural fold are neural crest cells and migrate outward to form PNS
- ecotoderm cells mirgrate over the neural tube and crest to cover nervous system
What are the 6 structures the neural crest cells form?
- PNS: sensory ganglia, autonomic ganglia, adrenal medulla, Schwann cells
- Calcitonin-producing cells of the thyroid
- melanocytes of the skin
What are teratogens?
substances that interfere with development causing defects or death
What is determination and what are two ways this can be accomplished?
commitment to a specific cell lineage
- uneven segregation of cellular material during mitosis
- morphogens that promote development down a specific cell line and a cell must have competency to respond to specific morphogens
What are the three groups of stem cells?
- Totipotent cells: able to differentiate into all cell types, including germ layers and placental structures
- Pluripotent cells: able to differentiate into all three of germ layers (all cell types except the placental cells)
- Multipotent cells: able to differentiate only into a specific subset of cell types
What are the four types of cell-cell communication?
- Autocrine signals act on the same cell that release the signal
- Paracrine signals act on local cells
- Juxtacrine signals act through direct stimulation of adjacent cells
- Endocrine signals act on distant tissues after traveling trhough the blood-stream
Define reciprocal induction?
if two tissues both induce further differentiation in each other
What are the major two steps in apoptosis?
- changes in morphology and divide into many apoptotic blebs
- These blebs are broken into apoptotic bodies to be digested by other cells and recycled
What is the primary difference between complete and incomplete regeneration?
Complete: damaged/lost tissue replaced with identical tissues
Incomplete: not replaced with identical tissue
What is senescence and what is it primarily caused by?
Biological aging
telomere shortening
What is the difference between umbilical arteries and umbilical veins?
Umbilical arteries carry dexygenated blood from the fetus to the placenta
Umbilical vienes carry oxygenated blood from placenta back to the fetus
What are the three phases of childbirth?
- Cervix thins out and the amniotic sac ruptures
- uterine contractions that are coordinated by prostaglandins and oxytocin
- birth of fetus, placents and umbilical cord expelled (afterbirth)
During early development states when do we start to see an increase in volume?
Blastula
Why are embryonic stem cells more controversial than adult stem cells?
Embryonic stem cells require the destruction of the embryo and adult stem cells do not require trascription factors to increase potency
What are the three main functions of the axon hillock?
- integrate incoming signal
- sum of incoming AP
- Begin AP
What two cells produce myelin?
oligodendrocytes in CNS
Schwann cells in PNS
What is the main purpose of microglia?
phagocytic cells that ingest and break down waste products and pathogens in CNS
Where are ependymal cells and what is their primary purpose?
line ventricles of brain and produce cerebrospinal fluid
What cells form the blood brain barrier?
Astrocytes
What are the three things the soma (cell body) contains in an axon?
- nucleus
- endoplasmic reticulum
ribosomes
What is a collection of cell bodies called in the CNS? PNS?
CNS–> nucleus
PNS–> ganglion
What is the voltage for when voltage gated Na channels get inactivated and voltage gated K channels open?
+35V
What is the difference between grey and white matter?
Grey: unmylenated
White: myelinated
What are the four division of the spinal cord
- cervical
- thoracic
- lumbar
- sacral
What structure protects the spinal cord?
vertebral column
Where is grey and white matter located in spinal cord?
grey matter is deep inside and white matter is outside
Where do sensory neurons enter on spinal cord? Motor neurons?
sensory neurons: found in dorsal root ganglia
moto neurons: exit spinal cord ventrally
What is the primary difference between somatic and autonomic nervous system?
Autonomic nervous system has two neurons. (Motor neurons in somatic nervous system go directly from spinal cord to muscle without synapsing)
Which neurotransmitter is associated with parasympathetic nervous system and sympathetic nervous system?
parasympathetic: Ach
sympathetic: preganglionic neurons release Ach but postganglionic neurons release norepinephrine
What is the vagus nerve?
Cranial nerve responsible for much of the parasympathetic innervation of the thoracic and abdominal cavity
What are the two types of reflex arcs?
- Monosynamptic: single synapse btw the sensory neuron and the motor neuron (ex: knee-jerk reflex)
- Polysynaptic: there is at least one interneuron between sensory and motor neuron (ex: withdrawal reflex–> step on nail and pull foot away but neurons in the muscle of opposite limb must be stimulated/ interneurons in spinal cord provide connection from the incoming sensory neurons to the motor neurons of supporting limb–> interneurons fire right onto motor neurons)
What are the three difference between tracts and nerves?
- Nerves are collection of neurons in PNS and tracts are collection of neurons in CNS
- Tracts contain only one type of info and nerves contains multiple types
- Nerves contain cells bodies in ganglia and tracts have cell bodies in nuclei
What are three traits of the somatic division of PNS?
- innervates skeletal muscle
- some parts are reflec arc
- can involve an array of different number of neurons
What are the three types of hormones?
- Peptide: charged, first messenger and binds to a receptor that triggers a second messenger (cAMP, IP3, Ca). change concentration of cAMP–> signal cascade/fast acting
- Steroids(gonads and adrenal cortex): receptors are intracellular/bind to induce conformational change and impact gene expression) slow acting/ need to be carried in blood bc not water soluble(carrier protein)
- Amino Acid derivatives: catecholamines (epinephrine and nonrepinephrin), thyroxine.
What is the difference between direct and tropic hormones?
- Direct hormones are secreted and then act directly on target tissue (insulin)
- Tropic hormones: require intermediary to act (Ex: GnRH released from hypothalmus triggers release of LH and FSH and then acts on gonads) Usualy orginate in brain and anterior pituitary gland
What is the suprachiasmatic nucleus?
receives some light input from the retina and helps control sleep-wake cycles
What are 4 hormones released by the hypothalamas and their reciprocal hormones released by the anterior pituitary?
- GnGH–> FSH and LH –> testosteron/estrogen
- GnGH–> GH
- TRH–> TSH –T3/T4
- CRF–> ACTH (promotes synthesis and release of glucocorticoid from adrenal cortex)
- PIF–> decrease in prolactin secretion
What hormones are released from posterior pituitary?
- oxytocin: stimulates uterine contractions and milk letdown during lactation
- ADH (vasopressin): increases reabsorption of water in the collecting duct of kidneys. ADH is released in response to increase plasma osmolarity or increased concentration of solutes within the blood
they are synthesized in hypothalamus and travel down axon to posterior pituitary
Where is prolactin released?
anterior pituitary
What are three direct hormones released by the anterior pituitary?
- Prolactin
- GH from anterior pituitary that is controlled by (GHRH from hypothalmus): stimulates muslce and bone growth
- endorphin: decrease perception of pain
What causes a release of prolactin secretion?
dopamine
What is acromegaly?
in adults with increase GH the small bones grow (hands, feet, head)
What are the two functions of the thyroid and what is it stimulated by?
- Thyroid stimulating hormone
1. setting basal metabolic rate
2. promoting calcium homeostasis
Where are T3 and T4 produced and what is there role?
- produced by the iodination of the amino acid tyrosin in the follicular cells of thyroid
- Increase in them will lead to and increase in cellular resp–> increase in protein and fatty acids turnover by speeding up synthesis and degradation of compounds
- TSH (released by anterior pituitary) and TRH (released by hypothalamus) act on negative feedback system and prevent further secretion of T3 and T4
Why three symptoms of hypothyroidism?
- weight gain
- slow respiration and HR
- intellectual disability and developmental delay (cretinism)
What are the two things follicular cells in thyroid produce?
- thyroid hormone
- C-cells (parafollicular cells): produce calcitonin (lower Blood Ca)
How many parathyroids are there and what is the feedback pathway?
- four of them sit on posterior surface of thyroid
- Produce PTH: antagonist to calcitonin –> raise blood Ca levels, decrease excretion of Ca by kidneys, increase absorption of Ca in gut through vitamin D, increase bone resorption (freeing up calcium)
Besides Ca, what homeostasis does PTH also promote? How is this act cancled out?
- PTH increases the resorption of phosphate from the bone and reducing reabsorption of phosphate in the kidney and promoting excretion
- but vitamin D promotes absorption of phosphate from the gut
What are the three catagories of corticosteroids released from adrenal cortex?
- glucocorticoids: regulate glucose levels and affect protein metabolism
- mineralcorticoids: salt and water homeostasis (mostly in kidney)
- cortical sex hormones
What are two glucocorticoids? Two functions?
- cortisol: stress hormone
- cortisone
- both raise blood glucose by increasing gluconeogenesis and decreasing protein synthesis. decrease inflammation
What is one mineralocorticoid?
Aldosteron: increase sodium reabsorption in kidney
What is the 5 step system that controls aldosterones released from adrenal cortex? How is it controlled? Does it change blood osmolarity?
- decreased blood pressure
- juxtaglomerular cells of kidney secrete renin
- this activates angiotensinogen to angiotensin I
- Angiotensin I is converted into angiotensin II by angiotensin-converting enzyme (ACE) in the lungs –> increase in BP
- adrenal cortex secreates aldosertone –> increase in plasma volume–> increase in cardiac output (aldosterone also increases K and H+ ion excretion)
once blood pressure is restored, decrease drive to stimulate juxtaglomerular cells of kidney to secrete renin
no change on blood osmolarity
aldosteron causes reuptake of Na in the kidney
How is Glucocorticoids stimulated?
- ACTH
What are two types of cortical sex hormones?
- Androgens (testosteron)
- estrogens
(females are more sensitive to androgens)
What is the hormone producing structure in the pancreas that is part of the endocrine system? What three cells make it up?
Islets of Langerhans which contain three types of cells
1) alpha: secrete glucagon
2) beta: secrete insulin
3) delta: secrete somatostatin
When is glucagon increased and what is it’s role?
- secreted during times of fasting
- increases glucose production by triggering glycogenolysis, gluconeogensis
What are two symptoms of diabetes?
- polyuria: increase urination
- polydipsia: increased thirst
What is the primary role of somatostatin? How is it stimulates?
- inhibits both glucagon and insulin
- high blood glucose and amino acid concentration stimulate secretion
What is the role of erythropoietin? Where is it released?
- kidney
- stimulates bone marrow to increase production of eythrocytes (RBCs) and secreted in response to low oxygen levels in blood
What is atrial natriuretic peptide (ANP)? What releases it?
- heart
- regulate salt and water balance, When cells in atria are stretched from excess blood volume, increase ANP and promotes excretion of sodium to increases urine. Antogonist of aldosteron because it lowers blood volume
no change on blood osmolarity
Where is thymosin releases and what is its role?
- thymus
- for T-cell development and differentiation
What is the 8 step pathway of respiration?
- Nares
- Nasal cavity
- pharynx: pathway for both food and air
- larynx
- trachea
- bronchi
- bronchioles
- aveoli: coated with surfactant that lower surface tension and prevents them from collapsing
What are four structures of the larynx?
- Glottis: opening of the larynx
- Epiglottis: covers the glottis during swallowing
- two vocal cords
What are the three layers around the lungs? Order from innermost to outtermost?
- Visceral Pleura
- Intrapleural: contains a thin layer of fluid that helps lubricate other pleural surfaces
- Parietal Pleura
What two muscles expand the thoracic caivity during inhalation?
- diaphragm contract
- external intercostal muscles contract: one layer of muscle between the ribs)
What two muscles pull the rib cage down to decrease intrathoracic volume during exhalation?
- internal intercostal muscles contract
- abdominal muscles contract
What are the 6 commonly tested lung volumes?
- Total lumg capacity: max volume of air in lungs when inhale (6-7 liters)
- Residual Volume: volume remaining in the lungs when one exhales
- Vital Capacity: the difference between the min and max volume of air in lungs
- Tidal volume: the volume of air inhaled or exhaled in a normal breath
- Expiratory reserve volume: the volume of additional air that can be forcibly exhaled after normal exhalation
- Inspiratpry reserve volume: the volume of additional air that can be forcibly inhaled after normal inhalation
What is the difference btw hypoxemia and hypercarbia/hypercapnia?
- hypoxemia: low [O2] in blood
- hypercarbia/hypercapnia: high partial pressure of CO2 in blood
How can you measure lung capacities and volume?
Spirometer
What are the small hairs in the nasal cavity called? What is their function?
vibrissae: they help trap particulate matter and inectious particles
What is the mechanism called mucociliary escalator?
clilia propel mucus up the respiratory tract to the oral cavity to be expelled or swallowed
What happens to the bicarbonate concentration in blood during acidemia? alkalemia?
acidemia: h+ increase so shift equilibrium to left to increase CO2 in blood and decrease biocarbonate/ increase respiratory rate so it can be exhaled out
alkalemia: decrease respiratory rate to increase CO2 concentration and shift equilibrium to right to get more H+ and bicarbonate
What are 6 immuno mechanisms in the respiratory system
- vibrissae in the nares
- Lysozyme
- mucociliary escalator
- macrophages
- mucosal IgA antibodies
- mast cells(have antibodies on surface)
Where is fluid (including blood) most likely to pool to cause lungs to collapse?
The intrapleural space that is bounded by the parietal and visceral pleurea
What might it be beneficial to provide postive end-expiratory pressure to a premature infants when given a ventilator?
-ventilatory will provide a high pressure to prevent the alveolar from collapasing because these infants lack surfactants
What is the difference between a nucleoside and nucleotide?
- Nucleosides are composes of 5 carbon sugar bonded to a nitrogenous base covalently linked at C1
- Nucleotides are formed when one or more phosphate groups are attached to C5 end of nucleoside
What makes telomeres and centromeres more tighly raveled even when the rest of DNA is uncondensed?
Have high GC content which increase H-bonding so association between DNA strands is very strong
What is the main purpose of DNA topoisomerase
alleviate the trosional stress from supercoiling and reduce the risk of strand breakage by introducing negative supercoiles
How does DNA polymerase read and replicate DNA?
Read: 3’–> 5’
Replicate: 5’–> 3’
Which direction do primases synthesize primers?
5’–> 3’ direction
What is the primary function of telomeres?
They protect the chromosome from losing important genes from incomplete replication of 5’end of DNA
What are antionocogenes?
function to stop tumor progression (need KO of both alleles for gene not to function)
What are the two genes that encode for enzymes involved in mismatch repair? When does mismatch repair happen?
MSH2 and MLH1 (MutS and Mutl in prokaryotes) detect and remove erros introduced during replication in S phase
-happens in G2 phase of cell cycle
What are four characteristics of nucleotide excision repair?
- Thymine dimers in DNA created by UV light are eliminated from DNA by necleotides excision repair
- endonucelase makes nicks in the phosphodiester backbone
- DNA polermase then fills in gaps in the 5’ to 3’ direction and sealed with ligase
- Occurs during G1 and G2 phase of cell cycle
What are four traits of base excision repair?
- Affected base is regonized (ex: cytosine deamination: loss of an amino group from cytosine and convert to uracil) and removed by a glycosylase enzyme
- endonuclease removes damaged sequence
- DNA polymerase and DNA ligase fill and seal gap
- Occurs during G1 and G2 phase of cell cycle
When does proof reading occur and what enzyme is responsible?
During S phase/ DNA polymerase
What are two traits of restriction enzymes?
- palindromic so the 5’ to 3’ sequences of one strand is identical to the 5’ to 3’ sequence of the other strand
- in bacteria they act as a defense mech against viral infection
What is hybridization? What do techniques take advantage of this?
joining of complementary base pair sequences
-used in PCR and then use southern blot to detect DNA
What is one defining trait of dideoxyribonucleotide? What does it cause?
no 3’ -OH end
What are the 4 structures involved in electrical conduction in the heart?
- SA node: in wall of right atrium and causes the two atria to contract simultaneously
- AV node (between AV valves): Signal is delayed here to allow the ventricles to fill completely before they contract
- Bundle of His and branched in intercentricular septum
- Perkinje Fibers: distribute the electrical signal throught the ventricular muscle
How are muscle cells in the heart connected? Purpose?
Intercalated discs, which contain many gap junctions directly connecting the cytoplasm of adjacent cells. Allows for coordinated ventricular contractions
What is the difference between diastole and systole?
Systole: ventricular contraction and closure of AV valves. High pressure in ventricles
Diastole: ventricles are relaxed, semilunar valves (pulmonary and aortic) are closed, and blood from the atria fills the ventricles. low pressure in ventricles
How do you find cardiac output?
CO=HRx Stroke Volume
What are the three portal systems in the body?
- Hepatic protal system: blood leaving capilary beds in the walls of the gut passes through the hepatic portal vein before reaching the capillary beds in the liver
- Hypophyseal portal system: blood leaving capillary beds in the hypothalamus travels to a capillary bed in the anterior pituitary
- Renal portal system: blood levaing the glomerulus travels through an efferent arteriole before surrounding the nephron in a capillary network called the vasa recta
What are the three components of blood?
- Erythrocytes: RBCs
- Leukocytes: WBCs/granulocytes/ Agranulocytes
- Platelets (thrombocytes): are cell fragments or shards released from cells in bone marrow known as megakaryocytes
What does thrombopoietin cause and where is it secreted?
Secreted by the liver and kidney and stimulates mainly platelet development
What are three specific macrophages?
- microglia: neurons
- Langerhans cells: skin
- Osteoclasts: bone
What does hematocrit measure?
measures the percentage of a blood sample occupied by RBCs (percentage points)
What does a sphygmomanometer measure?
measure BP
How is CO2 transported in plasma and how does pH change/affect hemoglobin?
- CO2 exists in blood in the form of HCO3-. CO2 encounters carbonic anyhydrase which creates carbonic acids which dissociates to form bicarbonate in the plasma.
- Increase in CO2 increase H+ ions and this shifts the the oxyhemoglobin curve to the right to decrease affinity of hemoglobin to O2 (Bohr Effect)
*oxygen and hemoglobin exhibit cooperative binding
What are the 6 stages after a clot forms ?
- When there is exposed collagen platelets sense this as an injury
- coagulation factors are released from the liver because they sense a protein called a tissue factor
- Activation of prothrombin
- Form Thrombin by Thromboplastin
- Thrombin converts firinogen into fibrin
- Fibrin forms small fibers that aggregate and cross link into a woven structure
How is a clot broken down?
By Plasmin which is generated by plasminogen
What happens if you open more capillary beds?
will decrease resistence of circuit and cardiac output will increase as a result
How does osmotic pressure and hydrostatic pressures change from the arterial to the venous end of a capillary bed?
Osmotic pressure remains constant
Hydrostatic pressures in the arterial bed is greater than the hydrostatic pressure at the the venous end so fluid moves out of arteris and back in at venous end (osmotic pressures is greater than hydrostatic pressures in venous end)
Should I know?
What is one start codon and three stop codons?
Start codon: AUG
Stop Codon: UAA, UGA, UAG
What three processes must occur to hnRNA before it exists the nucleus as mRNA?
- Splicing: in spliceosome, snRNA and snRNPs form a complex that recignizes the 5’ and 3’ end of splices sites in intro.
- 5’ Cap: a 7-methlyguanylate triphosphate cap is added to the 5’ end of hnRNA.
- 3’ Poly-A Tail: added to the 3’ end of the mRNA transcript
To start stranscription, where does RNA polymerase bind?
TATA box, which is located within the promoter region of the gene
Where does the small subunit of ribosome bind to in prokarytes and eukaryotes?
- Prokaryotes: bind to the Shine-Dalgarno Sequences in the 5’ untranslated region of mRNA
- Eukaryotes: small subunit binds to the 5’ cap structure
What protein is involved in translational termination?
Release factors bind to the termination codons, causing water molecules to be added to polypeptide chain–> this allow the peptidyl transferase and termination factors to hydrolyze the completed peptide chain from final tRNA
What 4 events can happen during posttranslational processing?
- Phosphorylation: add phosphate group by protein kinases to activate and deactivate proteins. Phosphorylation of serine, threonin, and tyrosine
- Carboxylation: addition of carboxylic acids
- Glycosylation: addition of oligosaccharides as proteins pass through ER and golgi to determine cellular destination
- Prenylation: addition of lipid groups to certain membrane-bound enzymes
In the Jacob-Monodo model, what is the difference between and inducible and a repressible system with operons?
- Inducible: repressor binds to operator under normal conditions. Turned on by an inducer pulling the repressor from the operator site (ex; lac operon)
- Repressor: trascribed under normal conditions. the repressor made by the regulator gene is inactive until it binds to corepressors to bind to operator site and turn off gene (negative feedback) (ex: trp operon: create tryptophan)
What are the four components of an operon?
5’
- Regulator gene: transcribed to form repressor protein
- promoter site: site of RNA polymerase binding
- Operator site: binding site for repressor protein
- Structural gene: the gene of interest; trascription is dependent on the repressors being absent from operator site
3’
What are the two domains of Transcription factors?
- DNA-binding domain
- Activation domain: allows for the binding of several transcription factors and other important regulatory proteins
In enhancers, what is the difference between signal molecules, transcription factors, and response elements?
- Signal molecules: steriod hormones or second messengers, which bind to receptors in nucleus
- These receptors are transcription factors to use their DNA binding domain to attach to a reponse element (particular sequence in DNA)
How do prokaryotes and eukaryotes increase variability of gene products?
- Prokaryotes: use polycistronic genes: start transcription in different sites within the gene leads to different gene products
- Eukaryotes: use alternative splicing, combing different axons in a modular fashion to get different gene products
What are the two structures transcription factors search for?
- Promoters
- Enhancers
What are five types of immune tissue found near the digestive system?
- GALT
- tonsils
- Adenoids (nose)
- Peyer’s patches (small intestine)
- Appendix
What are two leukocytes? What do they contain? where do they come from?
- granulocytes –> (NEB)neutrophiles, eoisinophiles, basophils
- agranulocytes: lymphocytes(antibody production), monocytes/macrophages
contain toxic enzymes and chemical
come from hemtopoietic stem cells
For B-cells and T-cells, what is …
- Site of development
- site of maturation
- major functions
- specific or nonspecific
- Humoral or cell mediated
- Bone marrow for both
- Bone marrow, spleen, lymph nodes for B ells, Thymus for T cells
- B cells produce antibodies and T cells coordinate immune system and directly kill infected cells
- both are specific
- B cells are humoral and T cells are cell-mediated
What are defensins?
antibacterial enzymes found on skin
What is the complement system and what are the two ways it can be activated?
it consists of a number of proteins in the blood that act as nonspecific defense against bacteria. punch holes in walls of bacteria
- classical pathway: require binding of antibody to pathogen
- alternative pathway: does not require and antibody
What are interferons? What are four functions?
proteins that prevent viral replication and dispersion
- cause nearby cells to decrease production of viral and cellular proteins
- decrease permeability of cells so harder for virus to infect cells
- upregulate MHC class I and II, increase antigen presentation and better detection of infected cells
- responsible for flu like symptoms
What is the difference between MHC I and II?
MHCI: all nucleated cells display this/ binds to antigens that come from inside the cell
MHCII: are displayed on antigen presenting cells (macrophages/dentritic cells/some B cells)/ involved in exogenous pathway
What receptor do both macrophages and dendritic cells have?
PRR( Ex: TLR): recognize the category of invader (bacterium, virus, fungus, parasite)
What are two functions of Natural Killer T cells?
- detect down regulation of MHC
- induce apoptosis in virally infected cells that do not presen MHC molecules (like cancer cells)
What are 4 facts about neutrophils?
- most abundant leukocyte in blood
- short lived
- phagocytic
- Target and detect bacteria through chemotaxis (movement of organism according to chemical stimuli/sense products given off by bacteria) and by bacteria that have been opsonized
What are three facts aboue eosinophils?
- have bright red-orange granules
- involved in allergic rxn and invasive parasitic infections
- when activated, release large amounts of histamines, which increase vasodilation and increased leakiness of blood veseels
What are 3 facts about basophils?
- contain large purple granules
- involved in allergic response (activated by allergens)/ release histamines (also mast cells)
- least abundant in blood
What are the three main possibilities for antibodies secreted into body fluids?
- once bound to specific antigen, antibodies attrach other leukocytes to phagocytize those antigens immediately (opsonization)
- antibodies may cause pathogens to clump together, forming large insoluble complexes that can be phagocytized
- antibodies can block the ability of a pathogen to invade tissues/neutralize the pathogen
What is the difference between binding of antigens to B cells and antigen binding to antibody on mast cell?
- B cell is activated, proliferation, memory cells
- cause degranulation (exocytosis of granule contents), releasing histamines
Why does it take so long to initiate an antibody response?
B cells undergo hypermutation of its antigen binding region, trying to find the best match for the antigen
only the B-cells that can bind the antigen with high affinity survive (clonal selection)
What is isotype switching?
B cells can change which isotype of antibody they produce when stimulated by specific cytokines
When a naive B cells is exposed to an antigen, what are the two things that are produced?
- Plasma cells: produce antibodies
- Memory B cells: stay in lymph node and await reexposure
What is the difference between T-cell/Bcell experiencing positive and negative selection?
- Positive selection: allowing only the maturation of cells that can respond to the presentation of antigen on MHC
- Negative Selection: causing apoptosis in cells that are self-reactive (activated by proteins produced by organism itself)
Happens in thymus for t cells
happens in bone marrow for b cells
What are the 4 major types of T-cells?
- Helper T cells (CD4 cells) secrete lymphokines, recruit other immune cells and increase activity. CD4 response to MHC II molecules
- Suppressor T -cells: Express CD4 and Foxp3. Help tone down the immune response once the infection has been contained. Promote self-tolerance
- Killer T cells (cytotoxic or CD8 T cells): kill virally infected cells by injecting toxic chemicals that promote apoptosis. CD8vrespond to MHC I
- Memory T cells
What structure returns lymph contents to blood?
Thoracic duct delivers fluid into the left subclavian vein
Why does a small amount of fluid remain in tissue if enter from artery and return into vien?
- Net pressure drawing fluid in at venule(hydrostatic pressure decreases and oncotic pressure draws fluid out) is less than the net pressure pushing fluid out
Which cell-cell junction is only found in plants?
Plasmodesmata
What is the enteric nervous?
collection of neurons that govern the function of the gastrointestinal system
What are the 3 parts the pharynx can be broken up into?
Pharynx connects the the mouth and posterior nasal cavity to the esophagus
- nasopharynx: behind nasal cavity
- oropharynx: back of mouth
- laryngopharynx: above the vocal cords
What are the 4 main anatomical divisions?
- fundus/ body: contain gastric glands
- antrum/ pylorus: contain pyloric glands
What are the folds of the stomach called?
rugae
What is the difference between the gastric glands and the pyloric glands?
- gastric glands respond to signals from the vagus nerve
- gastric glands have mucous cells, chief cells (produce pepsingogen), parietal cells (release HCl, kills microbes, denature proteins, release intrinsic factors to cause absorption of B12)
- pyloric cells release G cells that secrete gastrin (peptide hormone), which induce the parietal cells to secrete more HCl and signals to stomach to contract
What are the steps to get to pepsin?
pepsingogen (inactive)–> zymogen form of pepsin–> H+ from HCl cleave pepsinogen to pepsin
What are the three parts of the small intestine?
- duodenum: chemical digestion
- jejunum: absorption
- ileum: absorption
What 4 main things released in the duodenum?
- Bursh-border enzymes
- peptidases
- enteropeptidases: involved in activation of other digestive enzymes
- secretes hormones like secretin and cholecystokinin
What are the 4 main brush-border enzymes?
- Maltase
- isomaltase
- lactase
- sucrase
What are two types of peptidases?
- Aminopeptidase: remove N-terminal amino acid from a peptide
- Dipeptidases: cleave peptide bonds of dipeptides to release free amino acids
What two things does enteropeptidase activate? what does this lead to?
- Leads to activation of trypsinogen–>tyrpsin
- procarboxypeptidases A and B to active forms
What are two functions of secretin?
- Peptide hormone that causes pacreatic enzymes to be released into the duodenum
- Regulates the pH of the digestive tract by reducing HCl secetion from parietal cells and increasing bicarbonate secreation from the pancreas
What is an enterogastrone? Example?
- hormone that allows slows motilty through the digestive tract. Slower motility allows increased time for digestive enzymes to act on chyme (secretin)
What are three facts about cholecystokinin?
- secreted in response to entry chyme into the duodenum
- Stimulates the release of both bile and pancreatic juices.
- acts on brain to promote satiety
What are two enzymes found in saliva?
lipase and amylase
What are the cells that make up the majority of pacrease?
Acinar cells
What three enzymes are released as their zymogen form from the pancrease? What converts these enzymes into active form?
- trypsinogen
- chymotrypsinogen
- carboxypeptidases A and B
Enteropeptidase produced by the duodenum
How do the contents released by the acinar cells get into the duodenum? What are these 3 major contents?
- major and minor duodenal papillae
pancreatic amylase, pancreatic peptidases (trypsinogen, chymotrypsinogen, carboxypeptidases A and B), pancreatic lipase
What is the major pigment in bile?
bilirubin; byproduct of the breakdown of hemoglobin
How and where does the gallbladder release bile?
Upon release of CCK, the gallbladder contracts and pushes bile out into the biliary tree
What are 5 functions of the liver?
- glucogenesisi/glycogenolysis
- storage and mobilization of fats; gluconeogenesis
- produced urea from ammonia
- detoxifies chemicals
- produce bile/synthesize albumin and clotting factors
What are the 6 accessory organs of digestions and from what germ layer do they orginate from?
- teeth, tongue, salivary gland, liver, gallbladder, pancreas
Tess tought sally lions go pee
- they arise from the endoderm
What are the 4 fat soluble vitamins?
Vitamins DEAK
What are the three major sections of the large intestine?
- cecum: accepts fluid exiting the small intestine through the ileocecal valve and is the site of attachment for the appendix
- colon: absorb water and salts
- rectum: storage site for feces
What are the two things gut bacteria produce?
vitamin k and biotin
what are the four divisions of the colon?
- ascending, transverse, descending, sigmoid
What are 7 hormones that regulate feeding?
- ADH/vasopressin/aldosterone: promote thirst
- glucagon/ghrelin: promote hunger
- leptin/cholescystokinin: promote satiety
Where do the renal artery, vein, and ureter enter and exit the kidney?
through the renal hilum which is the deep slit in the center of the medial surface.
What is the Bowman’s capsule?
a cuplike structure around the glomerulus and leads to long tubule
What is the difference between the internal and external urethral sphincter?
- internal: consisting of smooth muscle and is contracted in normal state. under involuntary control
- External: consists of skeletal muscle and is under voltunary control
What muscle lines the bladder?
detrusor muscle
What is the micturition reflex?
bladder is full and stretch receptors cause parasympathetic nervous system to fire and detrusor muscles to contract –> this causes the relaxtion of internal urethral sphincter
What are 3 characteristics of the proximal tubule?
- amino acid, glucose, water soluble vitamins and salts are reabsorbed, also water
- solutes enter interstitium (connective tissue surrounding nephron) and are picked up by vasa recta to be returned to blood
- secretion of H+, K+, ammonia, urea
What are 3 traits of loop of henle?
- descending loop is only permeable to water and medulla has an increasing osmolarity as go deeper into descending loop (reabsorb water into vasa recta)
- vasa recta and nephron create countercurrent multiplier system: flow of filtrate through the loop is in opposite direction of blood through vasa recta so do not reach equilibrium and able to reabsorb water (filtrate is constatly being exposed to hypertonic blood)
- ascending loop is only permeable to salts and is impermeable to water (decreasing medullary osmolarity and increase reabsorption of salts)
What is the ascending diluting segment of the loop of henle?
cells lining the tube get larger and contain a lot of mitochondria which allow reabsorption of Na and Cl by active transport
so much salt is absorbed in ascending loop that the filtrate becomes hypotonic to interstitium/blood
dilution of urin
What are 2 traits of the distal tubule?
- responds to aldosterons, to promote sodium reabsorption, decrease urine volume
- secrete K+, H+, ammonia, urea
What are 3 traits of the collecting duct?
- responsive to ADH and V2P
- no futher reabsorption after this
- after filtrate leaves it collected in renal pelvis
What is the 10 step pathway of filtrate in excretory system?
- Bowman’s space
- Proximal Tubule
- descending loop
- ascending loop
- distal tubule
- collecting duct
- renal pelvis
- ureter
- bladder
- urethra
What is the 6 step pathway of renal vessel pathway?
- renal artery
- afferent arteriole
- glomerulus
- efferent arteriole
- vasa recta
- renal vein
Where does filtration occur?
Bowman’s capsule: movement of solute from blood into filtrate
What are the five layers of the skin from deepest to shallowest?
- Stratum basale: contains stem cells/proliferation of keratinocytes
- Stratum spinosum: cells become connected to each other and site of langerhans cells
- stratum granulosum: the keratinocytes die and lose nuclei
- Stratum lucidum: only present in thick, hairless skin
- stratum corneum: contains dozens of layers of flattened keratinocytes, barrier
What are the two layers of the dermis?
- papillary layer: right below epidermis/upper layer/consists of loose connective tissue
- Reticular layer: right below the papillary layer/sweat glands, blood vessels, hair follicles are here
What is the hyperdermis?
layer of connective tissue that connects the skin to the rest of the body (contains fat and fibrous tissue)
How can the body warm itself in cold conditions?
- vasoconstriction
- arrector pili muscles contract, causing piloerection(hair on skin to stand up) –> trap heat
- shivering and ATP is converted into thermal energy (brown fat has less effecient e transport chain so lose energy in form of heat)
What part of the kidney has the lowest solute concentration?
Cortex where the proximal tubule and part of distal tubule is. Solute concentration increases as one descends into the medulla, urin, and then renal pelvis
What are two fibers within skeletal muscles?
- Red fibers (slow-twitch fibers): have high myoglobin content and derive energy aerobically (contract slowly)
- White fibers(fast twitch fibers)contain less myoglobin, less iron, so lighter (contract rapdily)
What is myoglobin?
oxygen carrier that uses iron in a heme group to bind to O2, have red color
What are three facts about skeletal muscle?
- voluntary movt
- have sacromeres so appear striated
- multinucleated
What is myogenic activity?
smooth muscle can contract without nervous systems input (contract in response to stretch or other stimuli)
What are the two filaments that make up the sacromere?
- Thick: organized bundles of myosin
- Thin: made up of actin along with troponin and tropomyosin
What is titin in sacromere?
acts as a spring and anchores the actin and myosin filaments together, preventing excessive stretching of the muscle
What are the 2 different lines, two different bands, and one zone in sarcomere?
- M-line: runs down the center of the sarcomere, through the middle of myosin filaments
- Z-lines: define the boundaries of each sarcomere
- I-band: region containing only thin filaments
- H-zone: contains only thick filaments
- A band: contains thick filaments in entirety, including over lap with thin filaments
During contractions, what happens to H-zone, I band, the distance between Z lins, distance between M lines, and A band?
- H zon, I band, distance btw Z lines and distance btw M lines becomes smaller
A band stays constant because entire length of myosin filament, which does not change length but slides
What are T-tubules?
oriented perpedicular to the myofibrils and allows the sarcolemma to distribute AP to all sarcomeres
What is the 4 step pathway during an AP in sarcomere?
- Ach activates receptors on sarcolemma and sarcolemma spread signal through T-tubules. Ca2+ is released from SR and binds to troponin, triggering a conformation change in tropomyosin (tropomyosin is bound to troponin)
- this change exposes the myosine binding sites on the actin thin filaments
- free myosin heads bound to hydrolyzed ATP (power stroke to have sliding of actin over myosin) bind to exposed actin–> these cross bridges allow myosine to pull on actin, drawing thin filaments towards M-line (shortening of sarcomere)
- ATP binds to myosin, releasing it from actin. This ATP is hydrolyzed to recock the myosin head so that it is in position to initate another cycle
What is frequency summations and tatanus?
- freq summation is when contractions combine to become a stronger and more prolonged contraction
- tetanus: contractions become frequent and the muscle is unable to relax –> muscle fatigue
What two muscles exhibit myogenic activity?
smooth and cardiac
What are two supplemntal energy reserve in muscle to reduce oxygen debt?
- creatine phosphate is created by transfering a phosphate group from ATP to creatine in times of rest. the rxn can be reversed to generate ATP quickly if needed
- myoglobin: heme containing protein in a muscular oxygen reserve
What does spongy bone consist of?
trabeculea: bony points
What are the two different types of bone marrow?
- red: filled with hematopoietic stem cells (generate all cells in blood)
- yellow: composed of fat is inactive
What are the three regions of long bone?
- diaphyses: cylindrical shaft. full of bone marrow
- metaphyses: swell at end of diaphyses. full of bone marrow
- epiphyses: ends/ are spongy bone to handle force and pressure of joint/ had the epiphyseal (growth) plate, which is a cartilaginous structure and site of longitudinal growth
What are three facts about periosteum?
- fibrous sheath that surrounds the long bone to protect it
- is the site for muscles to attach
- cells of periostem may differential into osteoblasts
What two cells are responsible for buidling and maintaining strong bones?
- Osteoblasts: build bone
- osteocytes: poly nucleated macrophages that resorb bone
What are two substances that promote bone resorption?
- Parathyroid hormone: peptide hormone released by parathyroid glands in response to low blood calcium
- Vitamin D: activated by parathyroid hormone
What 2 facts about cartilage?
- consists of a firm but elastic matrix called chondrin (secreted by chondrocytes)
- avascular
What is the synovial capsule and what soft tissue is located there/what does it secrete?
synovial capsule, which encloses the joint cavity. A layer of soft tissue called synovium secrete synovial fluid, which lubricated movement
What does it mean for muscles to work in antagonistic pairs?
one relaxes while one contracts
What is the difference between an abductor and an adductor?
abductor: moves a part of the body away from midline
adductor: moves a part of the body towards from midline
what are immovable joints?
fused together to form sutures
What are the two divisions of the human skeletal system?
- Axial: consists of structures in the midline such as skull, rib cage
- Appendicular: consists of bones of the limbs, pectoral girdle, and pelvis
What are three main types of chromosomal mutations that do not share name with frameshift mutation?
- duplication:segment of DNA is copied mutliple times in the genome
- inversion: occurs when a segment of DNA is reversed in the genome
- Translocation: occur when a segment of DNA from one chromosome is swapped with a segment of DNA from another chromosome
What are the five criteria for Hardy-Weinberg Principle?
- pop is very large
- no mutations that affect the gene pool
- mating btw individuals in the population is random (no sexual selection)
- no migration of individuals into or out of the population
- genes in the population are equally successful at being reproduced
What does Hardy-Wiengberg equilibrium imply?
pop is not undergoing evolution, allele freq will remain stable over time
What is inclusive fitness?
measure of an organism’s success in the population based on the number of offspring, success in supporting offspring, and the ability of the offspring to then support others
What is modern synthesis model (neo-Darwism)?
adds knowledge of genetic inheretance and changes the gene pool to Darwin’s original theory. when mutations/recombinations result in changes that are favorable to the organism’s reproductive success, the change is more likely to pass on to the next generation
What is parallel evolution?
two species with a common ancestor remain similar because of similar evolutionary pressures
What is the definition of punctuated equilibrium?
considers evolution to be a very slow process with intermittent rapid bursts of evolutionary activity
What is the difference btween single corss overs and double cross overs?
- single effects happen at end
- DCOs effects happen in middle
What is a robertsonium translocation?
long arms fuse together which results in chromosome that has two long arms but short arms are avaible on other acrocentric chromosom
What are calcholmines?
hormones made by adrenal glands (increase HR and BP)
Hormones released from Anterior Pituitary?
FLATPEG
If nondisjunction occrus, what is the chance that the mother will pass either no copies of x chromosome and have child wqith Turner’s syndrome or pass two copies and have a child with Trisomy (Klinefelter’s Syndrome)? What is the chance of viable offspring?
100%
1-(nondisjunction probability)
What is miRNA?
single nucleotide strand incorporated into RNA w/ hairpin loop
Are siRNA double or single stranded?
double
What is hypoxia?
oxygen deprivation
What is beta oxidation?
Fatty acids are broken down into acetyl-Coa and fed into citric acid cycle
What is the difference between Micotubule depolymerization and Actin polymerization?
Actin polymerization: cell motility
Micotubule depolymerization: separating chromosomes
What is a retrovirus?
single stranded RNA and use reverse transcriptase to synthesize DNA
What are three facts of a normal distribition?
- 98% is greater than 3 SD from mean
- 95% is 2
- 65% is 1
What is the difference between a nucleotide and a nucleoside?
- nucleotide have a phosphate
What is a hexose?
6 carbon ring
How many H-bonds between A-T and G-C?
Three between G-C and two between A-T
What happens during P, T, and Q/R waves?
P waves: atria depolarization
Q/R: vetrical contractions so depolarization, Na+ flows in but not during T
T: repolarization so Na+ is pumped out
What part of mitosis are microfilaments used for?
cytokinesis
What part of mitosis involves microtubules?
separation of chromosomes
What is the range of human hearing?
20Hz-20kHz
How is pyruvate removed from mitochondria in gluconeogensis?
- pyruvate carboxylase converts pyruvate into oxolacetate in the mitochondira by adding -COOH
- Oxalacetate is converted into malate to be transported out of mitochondria
- once converted back to oxalacetate in the cystol it is converted to PEP by PEP carboxykinase
What is a major component of connective tissue (blood, cartilage, tendons…)
collagen
What is the function of Vitamin D?
acts similar to PTH and increase absorption of Ca+ in intestine
What is the difference between osteoblast and osteoclase?
Osteoblast: bone formation
Osteoclase: bone breakdown
How are steroid hormones transported?
can diffuse freely
but need plasma proteins to be transported in blood because blood is hydrophilic
Where are the two places steroid hormones can be produced?
adrenal cortex
gonads
Are steroid hormones longer or shorter lasting than peptide hormones?
longer lasting bc have genetic effects
What are 6 molecules made in krebs cycle?
citrate–> isocitrate–> succitate–> fumerate–> malate–> oxalcetate
What are the four stages of zygote?
“more blasting gas, I’m nervous”
- morula
- blastula
- gastrula (three germ layers)
- neuralation
WHat are the three stages of fertilization?
- sperm passes through the corona radiata, layer of follicular cells surrounding oocyte, and zona pellicida, layer of glycoproteins
- acrosome rxn, release of digestive enzymes so sperm nucleus can enter zygote
- zygote completes meisosis II and splits into mature ovum and polar body
What is a blastocyst? What are the three parts? Where does it implant?
fluid filled cell
- blastocoel (fluid filled cavity), trophoblast (outer layer), Inner cell mass (inner layer and give rise to fetus)
implants into endometrium
Rank the following from most to lease compact?
DNA Helix
heterochromatin
Nucleosome
Euchromatin
- Nucelosome
- Heterochromatin
- euchromatin
- DNA helix
What type of proteins are involves in epithelial cells structural integrity
intermediate filaments (ie. keratine)
How can muslces under voluntary control move involuntarily?
reflex arc
What are two clotting molecules?
1) Thromboxane: releases hormone from blood platelets/induces platlet aggregation and arterial constriction
2) Thrombin causes the cloting of blood by converting fibrinogen to fibrine
What is another way exons can be removed?
alternative splicing
What are two types/function of DNA polymerase in eukaryoted?
- alpha: initiates synthesis
- δ, which synthesizes new DNA strands complementary to a template and requires an existing 3’ hydroxyl (requires RNA primer)
What are ribonucleases?
degrade RNA
Where do RNA and DNA differ?
C2
What is a type of eicosonoid?
prostaglandins (5 Carbon ring), regulate inflammation
Where is proline found?
turns of protein
What is the lac operon?
repressor
What does a retrovirus need?
reverse transcriptase: DNA polymerase activity with RNA primer
What is high blood osmorlarity?
solute concetration is high, so conserve water and increase BP
What reduces blood osmolarity? Why?
ADH(peptide hormone/vasopressing) because increase H2O without changing solute levels
Does aldosterone (mineracorticoid) affect blood osmolarity?
no, increase Na+ absorption, increase K+ and H+ excretion
What does ANF do?
decrease BP, inhibit glomerula filtration, decrease aldosteron
What are leydig cells?
stimulated by LH and produce testosteron and androgens
What are chromaffin cells?
catecholamine (epinephrine/noepinephrin) secreating neuroendocrin cells of adrenal medulla
What are Granulosa cells?
follicular cells associated with female oocyte
-involved in corpus leteum and produce progesteron
What is the 5 steps to get to spermatids?
Spermatogonal stem cells –> spermatogonia–> (mitosis) primary spermatocytes–> (Meiosis) secondary spermatocytes–> (meiosis II) spermatids
What does sperm gain after spermiogensis?
10 formation fo acrosomal cap
2) formation of tail
3) loss of excess cytoplasm
What are faculative anearobes?
can live in presence or absence of O2
What is the somatic nervous system?
control muscles (peripheral)
What is the autonomic nervous system?
physiological response
What is the enteric nervouse system?
control gastrointestinal
What causes dizzness when stand up to fast?
drop in pressure (hypotension) blood pools in blood vessels of lower extremeties and less is returned to heart, so reduced blood flow to brain
What is the difference between a promoter and enhancer?
- promoter initiates transcription, near transcription site, only upstream
- enhancers is a short segment of DNA that can bind to TF (activators), can be upstream or downstream(cis acting)
What are Juxtaglomeral cells?
smooth muscle cells in kidney found in afferent arteries, which deliver blood to glomerulus
What is genetic bottlenecking?
is a redcution in gene-pool diversity because of a sharo reduction in pop size
What is the difference between allopatric and sympatric speciation?
Allopatric occurs bc of physical barriers (geographic isolations) and sympatric describes reproductive isolation that emerges when no physical barriers separate a populations
Arrest at which checkpoint is most likely to prevent the cell from dividing?
G1
Is collagen found in large vessels or capilaries?
large vessels, especially arteries
When would cortisol levels be at their highest?
when ACTH levels are at lowests, because negative feedback loop
When does gluconeogensis occur?
duering fasting
Why can’t acetyl-CoA be used for gluconeogensis?
acetyl-CoA cannot, when produced from the oxidation of even-chain fatty acids, serve as a substrate for gluconeogenesis. Conversion of pyruvate to acetyl-CoA is irreversible and during the TCA cycle, the two carbons of acetyl-CoA are lost as two molecules of CO2 and are not integrated into the carbon skeletons of TCA cycle intermediates that can be directed into gluconeogenesis.
What is acetyl-CoA converted to in Krebs cycle?
CO2
What does an increase in beta oxidation cause?
This increased mitochondrial beta-oxidation leads to an increase in TCA cycle flux and CO2 production
What are four functions of cholecystokin
Stimulating pancreatic acinar cells to release digestive enzymes, stimulating feelings of satiety (fullness) to suppress hunger, inhibiting stomach emptying, and lowering gastric acid secretion.
What is the function of somatostatin?
inhibits the release of CCK
What germ layer does the stomach come from?
endoderm
What germ layer do the spleen, born marrow, and kidney come from?
mesoderm
In an in vitro test of the pentose phosphate pathway, 30 moles of glucose 6-phosphate were used. In theory, how many moles of ribulose could you create using the 30 moles of glucose 6-phosphate?
one G6P is converted to a fiveC ribulose and 1 CO2
What is the direction of transcription of DNA to RNA?
antiparallel
What is the key step in citric acid cycle?
conversion of fumerate to malate
In a codon, where is a mutation least likely to lead to a big effect?
in the third base
How many electrons does water need?
2
What are the 4 different names for the complexes in ETC?
Complex I is known as NADH dehydrogenase, II is known as succinate dehydrogenase, III is known as cytochrome bc or c, and IV is known as cytochrome c oxidase
Which phases of the pentose phosphate pathway should be activated to produce the greatest amount of nucleotides and NADPH, respectively?
- NADPH is produced only in the oxidative phase of the pentose phosphate pathway. oxidative phase is irreversible (rate limiting step),
- Ribulose 5-phosphate, a product of both the oxidative and non-oxidative pathways, can be converted to ribose 5-phosphate, which in turn can be used to make nucleotides. carbon dioxide is lost in the non-oxidative phase. Thus, the non-oxidative phase yields more moles of ribulose 5-phosphate per mole of glucose 6-phosphate than the oxidative phase.
What are the two main functions of NADPH?
NADPH has two main functions: it serves as a reducing agent needed for the synthesis of lipids and nucleic acids, and it helps protect against damage from reactive oxygen species by regenerating the antioxidant glutathione from its oxidized form
How does grunting prevent aveoli collapse?
expiration against a positive pressure foces air into aveoli
What is one dangerous effect of positive-pressure breathing?
when air is forced into the lungs, pressure in the mediastinum (the cavity that houses the heart and largest vessels) increases. As fluid tends to flow from high to low pressure, this can partially occlude blood flow back to the heart. Negative-pressure breathing suffers from no such negative effects.
Does positive pressure breathing force air into or out of lungs?
into
What are two conditions that decrease tidal volume? Two that do not affect tidal volume?
- late pregnacy because uterus decreases area for lungs to expand/ narcotic overdose because decrease respiratory drive
- asthma does not because it is a result of the narrowing of the bronchioles, preventing effective movement into and out of lungs. pulmonary embolism is a circulatory not a respiratory problem
Why are red blood cells not able to produce MHC?
because do not have a nucleus
What is the effect of LH in females?
causes mature follicles to undergo ovulation
What hormones does the anterior pituitary gland releases that affects metabolism?
Thyroid stimulating hormone
Is ATP a second messenger?
no
How many rings are in steroids?
4 rings
What gland releases ACTH in response to CRH from the hypothalmus?
anterior pituitary gland
Stem cells that can differentiate into different connective tissue are what type of stem cells?
Multipotent
Why might a defect in splicing not be prevelant in population?
bc necessary for embryonic development
Can prokaryote RNA polymerase transcribe DNA?
yes
How many carbons in glutamate?
5
What two activities must Reverse Transcriptase have?
- RNA-dependent DNA Polymerase
- DNA-dependent DNA Polymerase because create double strand DNA from single strand RNA
How does insulin affect beta oxidation and lipid breakdown?
insulin inhibits it and promotes lipid synthesis
Does oxytocin affect milk production?
yes, allows release of milk
What germ layer do the longs come from?
endoderm
Where does fatty acid and sterol synthesis occur?
liver
where are lacteals located?
intestinal villi
what are centromeres made of? Arms?
heterochromatine
euchromatin
When does the egg leave ovary?
luteal phase: travel down fallopian tube, spike in LH triggers ovulation, high levels of progesteron to ensure uterine endometrium is ready
What type of receptors is L-glutamate?
GPCR
What are MHC class II cells?
C cells, dendritic cells, macrophages (antigen presenting cells)
What is hypertrophy?
enlargment
What is gastrin?
peptide hormone that stimulated secretion of HCL by parietal cells in stomach
What is somatostatin?
peptide hormone secreted by delta cells that inhibits insulin and glycagon and release is triggers by high glucvose and amino acid levels
What is one response from epinephrine?
activated GpCR and activated glycogen phosphorylase and inactivated glycogen synthase
What type of hormone is aldosterone?
steroid hormone
What type of hormone is T3/T4?
peptide hormone
What type of hormone is glucogan?
peptide hormone
What will be activated in kidneys if drop in BP?
renin-angiotension-aldosterone system (increase renin)
Do eukaryotes and prokaryotes both have supercoiling of DNA?
yes
What does long term development patter such as disease, tumor relate to?
steroid hormone defect
How do you transfer info from bacteria to eukaryote?
nuclear phage recombination
What is the difference between LH and FSH?
LH: ovulation
FSH: growth of ovarian follicule
How many oriC are there in bacteria?
one because circular
What is the difference between transfection and tranduction? Similiarity?
both include genes of bacteria in eukaroytes but transduction is through virus
What are the three differences between a promoter and enhancer?
Promoters initiate transcription, are near transcription site, and are upstream
enhances are short segments of DNA that can be bonded to TF to enhance transcription, are upstream or downstream, cis acting)
What is one cofactor in glycolysis?
Mg
How many protons are transfered in complex I in ETC?
4 protons
How many protons are transported in complex IV in ETC?
8 protons but 4 are given to O
When concentrated urine is being produced, in which of the following regions of the kidney will the glomerular filtrate reach its highest concentration?
medullary portion of collecting duct
What is before the medullary collecting duct?
cortical collecting duct
Where are lipid rich domains located on plasma membrane?
lipid rafts
Does brain need insulin to uptake glucose?
no, diffuse across blood brain barrier via Glut-1
What is the role of cytotoxic T lymphocytes?
target virus infected cells by recognizing the viral antigen presented on the cell surface of infected cells
What type of muscle is diaghphram?
skeletal muscle/ Ach
What ner innervates diaphram? which nerves do not?
phrenic nerve does, autonomic nerves do not
Where does the phrenic nerve orginate?
cerebral cortex (voluntary breathing), brain stem (involuntary control)
What is most likely to increase during viral infection?
aerobic respiration, pentose phosphate pathway(create nucleotides)
How does vitamin D impact phosphate and calcium levels?
increase absorption
What do all nucleated cells express?
MHC I
What do only antigen presenting cells express?
MHC II
Does shorter sacromere mean stronger contraction?
While it is true that shorter sarcomere length translates to a stronger contraction up to a point, too much overlap causes the actin and myosin filaments to bump together and reduces the strength of contraction.
What is released from beta oxidation?
CO2
What is produced by one round of beta oxidation?
1 acetyl-CoA, 1 NADH, 1 FADH2, decreasing the fatty acid chain length by two carbons
How does pregnancy impact lung volume?
pressure on diagphram so decrease tidal volume, must increase respiratory rate
What gives the urge to breath?
low Co2
What types of cells are good for distal and proximal tubule?
cuboidal because good for solute transport and absorption
What is ketoacidosis?
excess of ketone bodies sysnthesis during time of fasting, release of acetone in breath
What is necessary for synthesis of acetly CoA?
NADPH
Where does fatty acid formation and pentose phosphate pathway happen?
liver
What is asthma?
narrowing of bronchioles and does not alter tidal volume
What can narcotic overdose lead to?
decrease in respiratory drive, decrease in rate and dept of breathing
Where is the first point in kidney where you have urin?
collecting duct
What type of air is in residual volume?
deoxgenated air
What two traits characterize type 2 diabetes?
imparued secretion of insulin and insulin resistance
