Term
| Where do most steps of cellular respiration occur? |
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Definition
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Term
| What distinguishes the outer membrane of the mitochondria from the inner membrane? |
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Definition
outer = like plasma membrane; freely permeable to small molecules
inner = very evaginated for larger surface area; most things require transporters to cross it |
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Term
| What is the main input for the CAC? |
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Definition
| acetyl CoA from glycolysis or fatty acid breakdown |
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Term
| Is the isomerization of citrate to isocitrate by aconitase reversible or irreversible? |
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Definition
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Term
| What kind of reaction happens when NAD+ dependent isocitrate dehydrogenase converts isocitrate --> alpha ketoglutarate? |
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Definition
| the first oxidative decarboxylation |
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Term
| What kind of reaction takes place when alpha ketoglutarate dehydrogenase converts alpha ketoglutarate --> succinyl CoA? |
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Definition
| the second oxidative decarboxylation |
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Term
| What energy coupling takes place when succinyl CoA synthetase converts succinyl CoA --> succinate? |
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Definition
| release of energy from cleavage of thioester bond is coupled to phosphorylation of GDP |
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Term
| What is the only citric acid cycle step not in the matrix? |
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Definition
| succinate dehydrogenase converting succinate --> fumarate |
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Term
| What takes place when fumarase converts fumarate --> L malate? |
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Definition
| a stereospecific H2O addition |
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Term
| How does pyruvate dehydrogenase control metabolism? |
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Definition
| it is the irreversible conversion of pyruvate --> acetyl CoA |
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Term
| 2 primary control points for the control of citric acid cycle metabolism |
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Definition
1. alpha ketoglutarate dehydrogenase
2. citrate synthase |
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Term
| Why must the CAC intermediates be replenished? |
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Definition
| they are siphoned off as precursors for anabolic reactions |
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Term
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Definition
| hydrogen with an extra electron (2 valence electrons) |
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Term
| How is succinate dehydrogenase different from other dehydrogenase complexes in the CAC? |
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Definition
succinate dehydrogenase = transfers electrons to FAD (which can't just accept 2 electrons so it --> FADH2)
other dehydrogenase complexes = transfer hydride ions to NAD |
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Term
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Definition
| electrons are used to reduce a series of oxidized proteins with progressively higher affinities for electrons (positive E knot prime) |
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Term
| 4 complexes in the electron transport chain |
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Definition
1. complex I
2. complex II
3. complex III
4. complex IV |
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Term
| reduction potential (E knot prime) |
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Definition
| measure of how readily an oxidized molecule will accept electrons compared to the standard proton |
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Term
| formula for change in reduction potential |
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Definition
| reduction "reduction potential" - oxidation "reduction potential" |
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Term
| equation relating reduction potential & free energy |
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Definition
| standard free energy = -n(F)(reduction potential) |
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Term
| How many multi-protein complexes are in the mitochondrial respiratory chain? |
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Definition
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Term
| reaction for ETC complex I (NADH:Q oxidoreductase) |
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Definition
| NADH + Q + 5 H+ matrix --> NAD+ + QH2 + 4H+ IMS |
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Term
| reaction for ETC complex II (succinate dehydrogenase) |
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Definition
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Term
| reaction for ETC complex III (Q-cytochrome c oxidoreductase) |
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Definition
| QH2 + 2 cyt c ox + 2 H+ matrix --> Q + 2 cyt c red + 4 H+ IMS |
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Term
| reaction for ETC complex IV (cytochrome c oxidase) |
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Definition
| 4 cyt c red + 8 H+ matrix + O2 --> 4 cyt c ox + 2 H2O + 4 H+ IMS |
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Term
| What is the name for the key reaction in the electron transport chain? |
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Definition
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