Final Flashcards
rate of rejection for first and second allograft.
second gets rejected faster because of memory
baby allographs rejected faster or slower by mother compared to receiving skin grafts from rabbit d
allografts from baby were rejcected faster because mom has alreaduy been exposed to baby
MHC 1?
protein complex on surface of all celss besides red blood celss. it presents peptides
Which nimmune cells use MHC 1 to identify self
t cells. they scan MHC 1. they see if MHC1 and peptide are normal. will kill if they differ.
No peptide or MHC1
NK cells will kill the cell
MHC molecules resposible for protecting fetus from mothers immune syste
MHC 1G. they inhibit NK cells in mom
when did life arise what was it
3.5-4 bya. bacteria
enters citric acid cycle
acetyl coa
energtic coupling cellular resp v photosynthesis
cellular respiration (exergonic). releases energy to break down glucose to make ATP.
Photosynthesis. endergonic. needs sun energy to make glucose.
how exergonic power endergonic
atp hydrolysis. atp breakdown. exergonic. releases energy.
redox coupling. high energy electrons. nadh, fadh2. are transfered to poewr endergonic processes.
griffith.
mice. transformation. s gave letahlity to r
dna v rna
dna. less o2. thymine.
rna. one mroe 02. uracil
hershey and chase
sulfur - protein.
phosphorus - dna.
cellular resp. equation. oxidized v reduced? why does oxidizing electrons from glucose and moving them to CO2 release energy
c6H12O6 + 6O2 -> 6H20 + 6CO2 + ATP.
glucose is oxidized. loses electrons. turns to CO2.
oxygen is reduced. it gains electrons and forms water
steps in Cellular respiration? produces most ATP?
- glycolysis. 2. pyruvate oxidation. 3. Krebs cycle. 4. oxidative phosphorylation. OP produces most ATP
diffuse thru membrane?
small nonpolar O2, CO2, some small uncharged polar molecules, H2O, glycerol
where does Co2 we exhale come from? which parts of CR? role of O2 that we breathe? no O2?
CO2 comes from pyruvate oxidation and krebs.
o2 is final e- acceptor. required for ETC. less ATP would be produced w/o it
mutation? DNA polymerase? why can mutations change the fuctioning of proteins? which factors impact DNA polymerase speed and error rates?
mutation: change in DNA sequences. naturally occur from DNA rep or environmental factors.
Dna polymerase. synthesizes new dna strands.
mutations chnage function: altering amino acid sequence.
hypothesis of human evo?
modern humans eveolved in africa and then migrated out. genetic diversity highest in africa.
4 macromolecules
carbs, protein,lipid, nucliec acid
why are cells small
for a high surface area to volume ratio for efficient transprt of nutrients. faster diffusion, metabolicallhy efficient
lac repressor inactive
alwasys synthesizes lactose
endosymbiosis hypothesis.
eukaryotes orginicated from prokaryokes eaten by other prokaryotes
statges of mitosis
1.prophase, condense chromosomes
1.5 - prometaphase - nuclear envelope dissolves
2. metaphase - chromossomes line in mikddle.
3. anaphase - sister chromatids separate
4. telophase - reforming of nucleus
5/0 - interphase, most of cell cycle w GI S(dna rep), G2. not separating
four structures of protei
primary - sequence of amino acids
secondary - foliding into helices or pleated sheets
tertiary - 3d shape.
quarternary - not all- multiple polypeptides
why can you digest starch, not cellulose
starch - alpha bonds.
cellulose - beta bonds we dont have cellulase
how do pops evolve
natural selection, genetic drift, gene flwo, mutations
what types of molecules are transcription factors
protein
5 tenents of natural selection
overprodcution, variation, competition, selective advantage, reproduction
how does DNA polymerase replicate DNA
dna polymerase uses template strands. adds nucleotides to 3’ end. 5’-3’.
what colors of light will drive photosynthesis by green plants most efficiently
red nad blue light because they are absorbed by chlorophyll.
lwhere do light reactions v calvin cycle take place
light in thylakoid membranes
calvin in stroma
wheren does o2 that we breathe come from
water. because of light reactions of photosynthesis. It splits the water molecules.
equation of photosynthesis
water is oxidized to form o2. co2 is reduced to form glucose. it requires light energy to excite electrons which are passed through electron transport chain to generate atp and nadph for reduction of co2 in calvin cycle.
mitosis v meisois
meisois: has two rounds. 4 daughter cells. haploid. genetically unique because of crossing over and independent assortment.
mitosis: 2 daughter cells. diploid. genetically identical.
diplod v haploid
diploid -2n - somatic cells -supporr growth, development, tissue repair. mitosis.
haploid. n. half the number. gametes. sexual repro and combining during fertilization
miller and urey’s experiment.
abiotic synthesis of amino acids and nitrogenous bases could occur within the environment before life.
why are viruses not considered to be alive
they cannot replicate or transcribe DNA without a host. they don’t have a cytoplasm or a membrane. they don’t process energy or maintain homeostasis.
rna world hypothesis
first genetic material was RNA because they can self replicate. theu can fold into several distinct 3D shapes. they have enzymatic properties
explain bacterial resistance
those with higher resistance survive and reporduce so theres more with resistant phenotypes in subsequent generation
what do all viruses have
capsid -protein shell that surrounds genetic material dna and rna
content of early earths atmosphere v today
early - little oxygen. lots of water vapor. volcanic erupstions.
as earth cooled, water vapor- oceans hydrogen escaped. o2 more abundant.
vaccines for viral infections
vaccines are harmless variant of pagogen that stimuatles immune system. use memory cells.
why endosymbiosis is beleived
mitochondria and cholorplasts have enzymes and transport systmes same as bacterial. they have ribosomes and stuff to translate and transcribe. they are roughly the same size.
guard cells close/
stomata open: light available - co2 enter. high humdity - maximze co2 intake cuz water is not lost. water supply. low co2.
stomata closed: darkness, dont need co2. dry - minimze water loss. high temp - increases evap - keep water. water stress - reduce water loss. lots of co2. dont need more. pathogen attack. defense
what process drives water thru zylem
transpiration- evap
somata close?
transpiration stops. water stops moving up. happens when plant loses too much water
adaptations in platns that allow them to respond to evironmental stresses
hormones. they have a lot of genes.
what kinds of stress can plants respond to
drought, heat, cold, salt, herbivores, pathogens,
which immune system relies on pathogen specifc recognition of antigens
adaptive. memory cells. t + b have speicic cells for particular pathogens.
why are action potentials considered positive feedback mechanisms?
once the threshold is reached, voltage gated sodium ion channels open which causes further depolarization etc
role of hemoglobin
iron containing protein that transports O2
explain cooperativity in hemoglobin and how ph can change affinity for oxygen
cooperativity is the process by which the binding of oxygen to one subunit of hemoglobin influjences ability of other subunits to bind or release oxygen. ex of allosteric regulation. positive cooperativity: o2 binds slowly but each subsequent binds more easily..
in lungs - lots of o2. o2 binds easier.
in tissues - unloading - low o2 conc- release of o2 because tissues need it for CR
partial pressure of o2(21%) if air pressure is 520mmhg
.21x520=109.2
fetal v mother hemoglobin
fetal hemoglobin has more o2 molecules at lower o2 partial pressures. can maintain higher o2 levels
allergies get worse over time
b cell evo is rapid. produes better immune response with each exposure, even on allergens
na v k
na is high outside k is high inside.
sodium potassium pump actively transports 3 na out and 2 k in
depolarization
decreasei in magnitude of membrane. inside becomes more positive. na flows in. membrane potential is more positive
synaptic transmission
receptors that bind neurotransmitters trigger a change in postsynaptic membrane potential.
operon
cluster of genes under single promoter. in bacteria.
promoter, operator (on/off)m, structural genes, regulatory genes
which processes increase genetic variability in meiosis
crossing over, independent assortment, random fertilization
osmosis.hypertonic,iso,hypo
osmosis - passive movement of water across selectively permeable membrane. high to low water conc. low to high solute conc.
hypertonic: solute outside. water moves out. cell shrinks.
isotonic; equilibrium
hypotonic: solute inside cell. water moves in. swells cell.
role of calcium in neurons
neurotransmitter release and signal transmission. action potenetial propagation - chanells open and ca flow into neuron
role of calcium in muscle contraction
initiates muscle contraction. binds to troponin. exposes binding sites on actin for myosin. cross-bridge cycling - mysoin pulls actin. relaxation - calcium is pumped back to SR troponin returns. - atp required
oxidation v reduction
OIL RIG
what kinds speed up v slow down CR
speed up: ADP, coenzymes (NAD+, FAD)
slow down: ATP, NADH, FADH2
ETC work
electron donation - NADH + FADH2 donate e-.
e- transferv - e- pass thru complexes towards o2
proton pumping - energy from e- transfer pumps protons into intermembrane space to form gradient
o2 as final e- acceptor - o2 receives e- at end of chain and combines w protons to form h2o.
atp production - proton gradient drives ATP synthase to produce ATP thru chemiosmosis.
importance of
ETC
energy production - produces ATP. only in aerobic conditions - fianl e- accpetor.
efficienty
bohr effect in hemoglobin
hemoglobin and o2 binding affinity influenced by ph and co2. increase in co2/decrease in ph/more acidic/ high temp - released o2 more readily. tissues
decrease co2/increase ph/basic/low temp -binds better. lungs
lysogenic v lytic
lytic - rapid production of viral progeny and destruction of host cell, cro.
lysogenic - integration of viral genome into host genome (prophage) allowing virus to remain dormant and replicate with host DNA. c1.
c1 and cro determines if lytic or not.
environmental stressors - uv- turn lytic
quorum sensing
bacterial communication that enables bacteria to coordintate behavior based on pop density. acheived thru autoinducers. once threshold reached, bacteria alter gene expression andcan alter gene expression - bioluminescene.
lux operon
regulation via quorum sensing.
lux 1 - synthesizes autoinducer. - signaling moleucle that accumulates as bacterial population increases, triggering luxr autoinducer complex (transcription factor) when critical conc is reached.
lux r v- regulatory protein that binds to an autoinducer to form luxr-autoinducer complex. which activates lux operon and leads to luciferase production
luciferase - enzyme reponsible to catalyzing bioluminsent reaction - produces light.
how it works:
low pop density: lux 1 produces small amounts of autoinducer. conc is too low to bind to lux r, so lux r does not active lux operon. luciferfase production i sminimal, and no light.
high pop density: conc of AHL increases. once threshole, autodindcer nbinds to Lux R lux R nautoinducer complex binds to lux operons promotoer activating expression of genes involved in biolum. produces lgihg
