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81 Cards in this Set
- Front
- Back
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why have organisms evolved to oxidize sugar molecules? why does this type of molecule contain alot of energy?
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sugars (and gasoline) have many C-H bonds and its e' are equidistant from the nucleus which makes them easy to remove (vs 02, which is highly electronegative, which makes it a good e' acceptor)
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how is celllular resp like controlled combustion?
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-energy is released in stepwise process
-each process is catalyzed by enzymes (dehydrogenase) with a small activation energy -all exergonic processes - |
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name 3 stages of cell resp
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1. glycolysis
2. citric acid cycle 3. e' transport, chemiosmosis |
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an organism must execute all three stages of cell resp to extract energy from glucose T/F
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not all organisms have all three stages b/c not all three stages are required; all three stages are need to maximize that amt of energy that can be extracted from glucose
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glycolysis occurs in the mitochondrion T/F
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F: glycolysis occurs in the cytosol; everything else occurs in mitchondria
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name parts of mitochondria
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outer membrane, intermembrane compartment, inner membrane, matrix
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the mitochondria generates the most ATP, more than glycolysis T/F
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t: in euk, this is where citric acid cycle and e' transport occur, which generates the most ATP
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names of aqueous environments of mitochondria and chloroplast and thylakoid
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matrix vs stroma vs lumen
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why is glycolysis an ancient pathway
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- found in all cell (pro + eu)
- doesn't need oxygen (thus could have operated before oxygenic photosynthesis evolved) - occurs in cytosol of all cells |
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glycolysis produces ATP, not consumes ATP T/F
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f: glycolysis consumes 2 ATP over the first 5 stages of the energy investment phase; 4 ATP are made in the energy payoff phase
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glycolysis results in loss of carbon T/F
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f: no carbon is lost, it is evenly divided between the 2 pyruvates
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2 pyruvates evolved from 1 glucose contains same about of carbon and energy T/F
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f: pyruvates have same amount of carbon but less potential energy
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what are the products of glycolysis for 1 glucose molecule?
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4 atp
2 pyruvate + 2H20 2 NADH + 2H+ |
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what was invested in the energy investment phase?
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2 atp
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name three part of mitochondria involved in cell resp
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inner membrane, matrix, intermembrane compartment
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outer membrane aka cristae T/F
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f: inner membrane aka cristae
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atp net yield eqn for cell resp
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38-2=36ATP
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FADH is made and used during the citric acid cycle T/F
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f: made during citric; used during e' transport
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nadh is produced during ETC T/F
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f: nadh is used during etc, none is synthesized; nadh is synthesized during glycolysis (2) and and pyruvate oxidation (2) citric (6)
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when is ATP produced during cell resp
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glycolysis
citric chemiosmosis |
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the majority of ATP is produced during citric T/F
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f: 32 are made during chemiosmosis, 4 during glycolysis and 2 during citric
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what is the overall eqn for glycolysis
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glucose + 2NAD+ + 2Pi + 2 ADP
--> 2 pyruvate + 2 h20 + 2 NADH + 2H+ + 2ATP |
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tell me about NAD+
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NAD+ 2e' + 2h+ --> NADH + H+
collects e's the e's they collect are used to synthesize ATP |
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oxidized form of nicotinamide adenine dinucleotide
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NAD+
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reduced form of nicotinamide adenine dinucleotide
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NADH + 2H+
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# C of glucose
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6
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# C of pyruvate
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3
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what is pyruvate
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product of glycolysis, from 1 glucose makes 2 pyruvate; pyruvate is then oxidized
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what bridges glycolysis and the citric acid cycle?
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pyruvate DIFFUSES through pores in the outer mitochondrial membrane; it requires a CARRIER to pass through the inner membrane
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pyruvate is oxidized in the cytosol T/F
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f; it is oxidized once it enters the mitochondrial matrix
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name the parts of pyruvate that take part during the catalysis via the dehydrogenase complex
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decarboxylation: carboxyl group COO- lost as C02
dehydrogenation: oxidation of last 2 C to acetate and NAD+ is reduced to NADH acetyl group: react with coenzyme A |
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how many C-H bonds does acetyl CoA have?
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3
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what happens to the acetyl group in pyruvate?
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reacts with acetyl coenzyme A
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what are the two reactions that occur during pyruvate oxidation
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decarboxylation
dehydrogenation |
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what is oxidized during dehydrogenation?
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last 2 C of pyruvate are oxidized, NADH is formed
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transport proteins are required to move pyruvate from cytosol into the intermembrance compartment T/F
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f: transport proteins on inner membrane transport pyruvate from intermembrane compartment to matrix
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what are the products of pyruvate oxidation
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2 pyruvate = 2 nadh + 2co2 + 2 acetyl coA
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what are the products of 1 acetyl coA entering the citric acid cycle?
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3nadh + 1 fadh + 1 atp + 2 co2 + 1 coA
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T/F: products of citric acid cycle for 1 acetyl coA molecule: 3nadh + 1 fadh + 3 atp + 3 co2 + 1 coA
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f: 3nadh + 1 fadh + 1 atp + 2 co2 + 1 coA
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there is no more C after pyruvate oxidation T/F
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f: no more after citric acid cycle
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all the PE in glucose after citric acid cycle is in the form of NADH + FADH2 T/F
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t
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FADH2 is produced during ETC T/F
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f: fadh2 is produced during citric acid cycle
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who are the donors and acceptors in the ETC
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nadh + fadh2 --> o2
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describe the ETC and its components
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4 inner membrane protein complexes: 3 integral + its prosthetic groups, 1 peripheral;
2 mobile e' carriers: ubiquinone: inner membrane, hyrophobic, 1-->2-->3 cytochrome c: intermembrane compartment: 3-->4 |
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integral and peripheral inner mebrane proteins transfer e' in the ETC T/F
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f: it's actually the prosthetic groups attached to the proteins (e.g. heme) that are redox cofactors (alternating b/w oxidized and reduced) that transfer e' in the ETC
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why is the ETC consisting of spontaneous reactions?
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b/c of the way the e' carriers are organized: you start with the highest free energy/least electronegative to the most electronegative e' carriers: from NADPH and FADH2 to O2
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how does the ETC start?
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NADH from the matrix reduces the prosthetic group of protein complex 1, then donates to ubiquinone
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what happens at the end of the ETC?
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o2 is reduced to h20
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FADH2 has more free energy than O2 T/F
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t
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no ATP is formed during ETC T/F
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t
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what are the components of the proton-motive force and what is its significance
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a. potential energy in concentration gradient
b. voltage energy: h+ are charged this is the the free energy GENERATED by ETC which POWERS chemiosmosis |
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what type of work does chemiosmosis do?
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prokaryote flagella; generate ATP in chloroplast for calvin cycle; ATP synthase in mitochondria
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what is chemiosmosis
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the ability to harness the force of the proton motive force to do work
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where is ATP synthase located
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inner mitochondrial membrane
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what powers oxidative phosphorylation
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ATP synthase in inner mitochondrial membrane
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what is oxidative phosphorylation
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a type of chemiosmosis: using the proton gradient built up by ETC to power ATP synthase to synthesize ATP
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ATP synthase in mitochondira, chloroplast, an plasma membrane of prokaryotes is identical T/F
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t
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how can the ETC and chemiosmosis be uncoupled?
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by interrupting the generation of the proton motive force, by ionophores or uncoupling transmembrane proteins that create h+ leaks across the innter mitochondrial membrane
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ATP synthase is an active transport pump T/F
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f: it is an active transport pump working in reverse: ATP synthase makes ATP; protein pumps hydrolize ATP
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describe the location of parts of h+ flow in ATP synthase
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H+ flow from intermembrane compartment --> matrix;
h+ enter through stator; attach to rotor; conformational change of rotor; rotor spins; catalytic sites on knob/headpiece which dangles in matrix is activated to produce ATP |
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name the protein complexes of the mitochondrial ETC
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1: NADH hydrogenase
2: succinte hydrogenase 3: cytochrome complex 4: cytochrome oxidase |
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where does proton translocation occur? and what is it
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it occurs at integral protein complexes 1 (NADH hydrogenase) and IV (cytochrome oxidase)
where protons are pumped from the matrix to the intermembrane compartment |
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more h+ = higher/lower pH?
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lower pH
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H+ quantity and pH are directly or inversely proportional?
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inversely
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name 2 sources of the proton gradient accumulated in the intermembrane compartment
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1. nadh
2. ubiquinone gets oxidized at complex III (cytochrome complex) while it picks up protons along the way (from nadh hydrogenase --> succinyl hydrogenase protein complexes) |
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what parts of atp synthase spin?
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rotor, knob
stalk, headpiece |
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compare and contrast photosynthesis and cell resp
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cell resp is combustion of glucose/sugar, yielding atp, water, co2; photosynthesis is products of combustion combined to yield O2 and sugar
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what enzyme is needed to substrate level phosphorylation
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kinase enzyme + high energy substrate + ADP
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where does substrate level phosphorylation occur?
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glycolysis + krebs cycle
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what occurs during the energy investment phase of glycolysis?
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1. ATP phosphorylation
2. isomerization of glucose6phosphate 3. ATP phosphorylation 4. hydrolysis of glucose6phosphate into 2G3P, 3C each |
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how is NADH made during glycolysis?
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each G3P loses 2 e' and 2 H; 1 of those H make NADH;
the G3P gains a P from the cytosol to become 1,3biophosphogylcerate |
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what happens during energy payoff stage of glycolysis?
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G3P loses 2 H to reduce NAD+; G3P gains a P from cytosol so now it has 2
substrate level phosphorylation of one of G3P's P remaining P is rearranged H2O is released substrate-level phosphorylation of last P to yield pyruvate |
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what happens to the phoSphates during energy investment phase of glycolysis?
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2 phosphates are added to sucrose and split into 2 G3P, each with 1 P
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what happens to the phoSphates during energy payoff phase of glycolysis?
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starting off with 1, it gains another form the cytosol, then they are both lost to make 2 ATP;
this happens for each G3P which yield 4 ATP overall in 1 turn of glycolysis |
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energy payoff stage starts with 1 P per G3P T/F
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t
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what does the citric acid cycle start with
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2 C acetyl + 4 C oxaloacetate = 6C citrate
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how many C in pyruvate?
how many C in acetyl CoA? |
3, 2, CO2 is released
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how is ATP made in the citric acid cycle?
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substrate level phosphorylation: phosphate is picked up by GDP, making GTP, which transfers the P to ADP, to make ATP (the P also makes the CoA fall off succinyl CoA to make succinate)
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how is FADH2 made in the citric acid cycle?
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succinate 4C is oxidized: 2 e' and 2H are lost and transferred to FAD
succinate becomes fumarate 4C |
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loss of a C means what
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probably that C02 was released
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what happens to the C is citric acid cycle?
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2 from acetyl coa + 4 from oxaloacetate = 6 to citrate; 2 are released from isocitrate and alphaketoglutarate; resulting in 4 for the rest of the cycle, until it starts all over again with the same 4 in oxoaloacetate
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