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51 Cards in this Set
- Front
- Back
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what is cellular respiration?
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oxidation of acetate to CO2, reduction of O2 to H20
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where does cellular respiration occur?
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mitochondria
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what is a general overview of energy production?
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1. acetylCoA produced from carbs, fat, or proteins
2. generates reducing equivalents from electron transport 3. reducing equivalents generate a proton gradient to drive ATP synthesis |
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what are the ways to get aceytl CoA?
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from amino acids, fatty acids, glucose (to pyruvate via pyruvate dehydrogenase complex)
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which tissues can NOT use fatty acids for acetyl CoA production?
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brain
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what are the other names for TCA cycle?
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citric acid cycle, kreb's cycle
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what does amphibolic mean?
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important in both anaerobic and catabolic processes
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what does TCA cycle take in and give out?
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takes in acetyl CoA, gives out NADH, FADH2
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what does the electron transport chain take in and give out?
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NADH, FADH2 in, ATP out
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what is step 1 of TCA cycle?
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pyruvate dehydrogenase take spyruvate to acetyl CoA.
irreversible decarboxylation |
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what are the cofactors of PDH?
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thiamine, niacin, riboflavin, pantothenate, lipoate
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how many complexes are there in PDH?
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3
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What is a cofactor of E1?
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thiamine pyrophosphate (TPP)
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what is a "biological tether" component of E2?
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lipoate
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what are examples of biological tethers?
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lipoate, biotin, b-mercaptoethylamine
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what are the 3 enzymes of the phyruvate ehydrogenase complex?
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1. pyruvate dehydrogenase
2. dihydrolipoyl transacetylase 3. dihydrolipoyl dehydrogenase |
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what is FAD usually associated with?
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proteins
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what is NADH usually associated with?
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soluble
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what does E1 of PDH bind?
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TPP
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what does E2 bind?
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lipoate, acetyl
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what doe E3 bind to?
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FAD
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where else are E1, E2, and E3 found?
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alpha keto glutarate dehydrogenase
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what inhibits pyruvate dehydrogenase?
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ATP, NADH, AcCoA, long chain fatty acids
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what activates pyruvate dehydrogenase?
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AMP, NAD, CoA
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what are the 3 levels of regulation of pyruvate dehydrogenase?
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1. allosteric- energy c hange
2. covalent modification- phosphorylation of E1 INACTIVATES 3. end product inhibition |
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where does the TCA cycle occur?
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mitochondrial matrix
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what is substrate level phosphorylation?
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production of ATP without ETC (Oxidative phosphorylation)
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what is step 1 of TCA cycle?
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condensation
conversion of acetyl CoA and oxaloacetate to citrate via citrate synthase irreversible. |
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what kind of acid is citrate?
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tricaboxylic
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is citrate chiral?
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NO, but it behaves asymmetrically. It is actually PROCHIRAL
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what is in the center of aconitase?
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Fe-S structure
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What is aconitase?
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catalyzes transformation of citrate to isocitrate (moves an OH via dehydrtaion/hydration)
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how is isocitrate converted to alphaketoglutarate in step 3?
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isocitrate dehydrogenase via oxidative decarbxylation
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what can alphaketoglutarate transaminate to?
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glutamate
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what is step 4 of tCA cycle?
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alpha-ketogluarate to succinyl CoA via a-ketogluarate dehydrogenase complex
this step is the 3rd loss of CO2 irreversible |
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what happens in step 5?
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substrate level phosphorylation
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what is sucinyl-CoA converted to in step 5?
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succinate, via succinyl CoA synthetase
not a favorable rxn, b/c hydrocarbons are very unreactive. |
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what happens in succinate dehydrogenase dehydrate in step 6?
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succinate is comverted to fumarate via succinate dehydrogenase.
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what happens in step 7 of TCA, hydration?
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fumarate is converted to L-Malate via fumarase
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what happens in step 8, dehydration?
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L-malate converted to oxaloacetate via malate dehydrogenase
very favorable. *NADH is formed in this step |
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what are the TCA cycle products?
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3 NADH, 1FADH2, 1GTP, 2 CO2
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what are inhibitors of TCA cycle?
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ATP, NADH, citrate, succinyl CoA
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what are activators of TCA?
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ADP, Calcium (b/c in muscles contraction indicates a need for more ATP production)
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what does oxaloacetate transaminate to?
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aspartate
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what is the only membrane associated component of TCA cycle?
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succinate to fumarate, making FADH2
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what does amphibolic mean?
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catabolic and anabolic nature of TCA cycle intermediates
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what does anapleurotic mean?
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reactions replenish pathway intermediates.
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what is the most important reaction in the liver?
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PEP carboxylase production of OAA
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what happens if there is a mutation in fumarase?
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kideny and smooth muscle problems, leiomas
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what happens if there is a mutation in succinate dehydrogenase?
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problems in the adrenal gland, pheochromocytomas
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what happens if fumarate and succinate build up?
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activates Hif1a (hypoxic conditions). this stimulates glycolytic enzyme synthesis
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