Question | Answer |
v-type pumps | uses pyrophosphate (PPi-> 2Pi) |
pH 3 is | 1 mmol concentration of H+ |
ion channel proteins | favored by membrane potential |
proton antiport proteins into vacuole | Na, Ca, sucrose (H+ out to make it favorable) |
tight junction | prevents flow between cells in the intestinal tract |
how is glucose taken up? | 2 Na+ for every 1 glucose then ATPase removes the Na+ (also osmosis is occurring with water) |
3 main types of neurons | sensory, interneurons, motor |
why are action potentials uni-directional? | refractory period of Na+ gated channels on other side that just opened |
action potentials are a ___ ____ ____ | positive feedback loop |
what returns membrane potential back to normal? | K+ voltage gated (out) and leak channels |
voltage gated K+ channels are also called | shaker channels b/c of fruit flies that shake due to deficiency of them |
where does depolarization occur? | Nodes of Ranvier, not in places where myelin is present |
series of events at neuromuscular junction | action potential, Ca2+ channel opens, synaptic vesicle fuses w/ membrane, neurotransmitter release, acetylcholine binds, Na+ in, Ca2+ released into cytosol, muscle contraction, P-class pump moves Ca2+ back into SR |
axon hillock | depolarization must reach potential for an AP to go; all or none principle |
how do local anesthetics work? | block Na+ channels in sensory neurons |
where does the majority of ATP in neurons go? | Na/K pump (3 Na out 2 K in) |
patch clamping | salty solution over a single channel, then an electrode inside; measure current and potential |
ΔG total= | ΔGconc + ΔGvolt |
ATP hydrolysis pkg/kcal per mol | about 8 pkg; 10-12 kcal/mol |
ΔGconc at 300K | -1.4 x log C0/Ci (i=intended not initial) |
ΔGvolt= | zFV (charge x 23 x volt) |
which transporter transports glucose from enterocyte? | glut-2 |
pmf= | V + 60 mV x ΔpH |
ion motive force= | V + 60 mV x log (C0/Ci) |
simplified Nernst equation | V=60 mV x log (C0/Ci) |
Valinomycin | allow K+ to transfer across |
Nigericin | K+/H+ antiport ionophore |
A23187 | Ca2+ ionophore |
CCCP | H+ ionophore |
NH4+ | H+ ionophore |
Gramicidin | nonspecific pore ionophore |
TPP+ | lipophilic cation, delocalized charges |
anabolic pathways are (4) | endergonic, divergent, reductive, NADPH intermediate |
catabolic pathways are (4) | exergonic, convergent, oxidative, NADH intermediate |
reduced have __ ___ electrons | high energy |
oxidized have ___ ____ electrons | low energy |
negative E0 | strong electron donor |
positive E0 | strong electron acceptor |
what is required to break down very large FAs? | peroxisomes |
2 regulated enzymes in glycolysis | hexokinase and phosphofructokinase |
pyruvate -> acetyl coA what enzyme? | pyruvate dehydrogenase |
reactions in mitochondria | pyruvate -> acetate + CO2 + NADH |
guanine vs adenine | guanine has a double bond oxygen |
FAD/FMN | flavins |
max ATP made from one glucose | would be 38 but 2 used up to get into mitochondria |
palmityl coA -> | 31 NADH + 15 FADH2 + 8 ATP = 131 ATP |
lactate -> pyruvate cost | 6 ATP in liver (back to glucose) |
0-3 secounds | ATP stocks |
2-10 seconds | creatine-P |
7-60 seconds | anaerobic metabolism + respiration |
1min- 90 min | respiration (glucose and fats) |
over 90 minutes | fats only |
pmf is used for ___ in bacteria | motility |
oxidation is ___ to pmf generation | coupled |
type 1 redox carriers | capacity for protons and elctrons (ubquinone) |
type 2 redox carriers | capacity for only electrons (heme) |
ferric | 3+ |
ferrous | 2+ |
why does the ETC use each complex rather than just jumping down? | specific binding |
complex 4 and 1 are | conformational pumps |
ubiquinone and complex III are | redox loops |
why isn't 3 H+ enough per ATP? | 8-9 actual; UCP, cotransporters use energy |
Cellular work ___ the ____ ratio | lowers the ATP/ADP ratio (metabolism is coupled) |
Best sustained oxygen consumption (mitochondria experiment) | ADP, Pi, pyruvate, hexokinase, glucose |
Phloem | sugar export |
Xylem | H2O transport |
___% of O2 production occurs in the oceans | 50% |
light reactions | occur in thylakoid membrane, NADPH and ATP formed |
calvin cycle | occurs in stroma; CO2 fixed and reduced to sugars (NADPH and ATP consumed) |
The ion in chlorophyll is | magnesium |
Chlorophyll protein | LHC (I and II) |
How many electrons per oxygen produced? | 4 |
How many electrons can PQ pick up? | 2 |
Photosystem I | light energy removes electron from P700 (ferredoxin), reduce NADP+, replenish electrons from plastocynanin |
Strongest oxidant in nature | PS II |
Strongest reductant in nature | P700 (ferredoxin) |
Small trick of photosynthesis | reduce NADP with electrons from water + build pmf |
Big trick of photosynthesis | split water without causing damage |
Cyclic electron flow | no NADPH made, just ATP synthesis (bacteria do this) |
Pmf chloroplasts | pH |
Pmf mitochondria | voltage |
Complex I/II are like | PS II |
Ubiquinone is like | plastoquinone |
Cyt B/C complex is like | cytochrome B/F complex |
Cytochrome C is like | plastocyanin |
CytC oxidase is like | PS I |
Uncouplers + 2 examples | decreased ATP synthesis, increased electron transport, ammonia and dinitrophenol |
Blockers + example | decreased ATP synthase and decreased electron transport, cyanide |
Most abundant enzyme on the planet | RuBisCO |
Per GAP produced, use | 3 CO2, 9ATP, 6NADPH |
2 major fates of GAP | conversion to glucose/starch in chloroplast; export for sucrose synthesis |
why do chloroplastic genes exist? | debunk protein to protect PS II |
how to prevent light damage (5) | light regulation, cyclic electron flow, feedback inhibition of PS II, repair of PS II, photorespiration |
photorespiration | rubisco can react w/ O2 to form 2-P-glycolate (toxic) then convert to triose (costly) |
photorespiration 3 organelles | chloroplast, peroxisome, mitochondria |
special c4 anatomy | mesophyll don’t have RuBisCO, bundle sheet cells have RuBisCO but limited PSII (corn is like this) |
glycolysis oxidation step | 6 |
glycolysis substrate-level phosphorylation steps | 7 and 10 |
complex III aka (2) | coenzyme Q, cytochrome C reductase |
complex IV aka | cytochrome oxidase |
How many net ATP are produced anaerobically per glucose? | 2 |
How many net ATP are produced with the complete breakdown of one glucose under aerobic conditions in a eukaryote? | 36 |
how many NADPH used per carbon atom? | 2 |
how many ATP used per carbon atom? | 3 |