Flashcards
BMS07-1029-TCA Cycle and Oxidative Phosphorylation
Flashcards do conjunto (31)
- 1Where does the Link Reaction occur?In the cytosol of the cytoplasm
- 2What occurs in the link reaction? What is added? What enzyme is needed? What is reduced?Pyruvate undergoes oxidative decarboxylation to acetyl CoA
CoASH is added
Pyruvate dehydrogenase
NAD+-->NADH+H+ - 3Where does the TCA Cycle occur?Mitochondrial matrix
- 4What is the TCA cycle?Cycle of oxidations of acetyl CoA to produce intermediates
- 5What does the TCA cycle produce?3 NADH+H+, 1 FADH2, 1 GTP
(10ATP in total)
Converts acetyl CoA to 2 CO2 - 6What is the order of events in the TCA cycle?1. Acetyl CoA
2. Citrate
3. Isocitrate
4. Alpha keto glutarate
5. Succinyl CoA
6. Succinate
7. Fumarate
8. L-Malate
9. OAA - 7What does citrate synthase do?Convert Acetyl CoA to citrate
- 8What does isocitrate dehydrogenase do? What is reduced/produced?Oxidises isocitrate to alpha-keto glutarate
NAD+-->NADH+H+
Produces CO2 - 9What does alpha-ketoglutarate dehydrogenase do? What is reduced/produced?Oxidises Alpha-ketoglutarate to succinyl CoA
NAD+-->NADH+H+
Produces CO2 - 10When is CoASH removed in the TCA cycle?When succinyl CoA becomes Succinate using succinyl CoA synthase
(GDP-->GTP+Pi) - 11What does succinate dehydrogenase do?What is reduced/produced?Oxidises succinate to fumarate
FAD-->FADH2 - 12What does malate dehydrogenase do?What is reduced/produced?Oxidises malate to OOA
NAD-->NADH+H+ - 13What are the three irreversible steps of the TCA pathway where allosteric regulation occurs?1. Acetyl CoA-->Citrate via citrate synthase
2. Isocitrate-->Alpha-ketoglutarate via isocitrate dehydrogenase
3. Alpha-ketoglutarate-->Succinyl CoA via alpha-ketoglutarate dehydrogenase - 14What are the intermediates produced during the TCA cycle used for?Succinyl CoA-->Hemes
Alpha ketoglutarate can undergo transamination to become glutamate
Oxoloacetate can undergo transamination to become Aspartate - 15What is oxaloacetate produced by the TCA cycle used for?Can become phosphoenolpyruvate, then undergoes reverse glycolysis to form glucose (gluconeogenesis)
- 16What is oxidative phosphorylation?The transfer of H atoms to O2 for the purpose of energy trapping/synthesis
- 17What does oxidative phosphorylation yield?30/32 ATP
- 18Where does oxidative phosphorylation happen?Inner mitochondrial membrane
- 19Which complex in the e- transport chain can FADH2 reduce?Complex II
As a result, FADH2 will have fewer protons being pumped into the inter membrane space as electrons are only supplied at complex 2 - 20Flavin cofactors and CoQ are...H+ acceptors
- 21Iron sulphur proteins and Cytochrome proteins are...Electron acceptors
- 22In the E- transport chain, electrons flow in what direction?from carriers with a more negative redox potential to a more positive
- 23What are the steps of the e- transport chain?1. NADH-->NAD+ by donating two electrons to Flavin MonoNucleotide in Complex 1
2. FADH2 also supplies 2 electrons but only in complex 2
3. Electrons are passed from one electron carrier to the next (Complexes II/Coenzyme Q, III,Cytochrome C oxidase, IV) until the last cytochrome of the chain (Cyt a3), which passes its electrons to oxygen
4. Oxygen also picks up 2H+, forming water - 24What is the energy from the e- transport chain used for?Pump protons from inner mitochondrial membrane to intermembrane space, creating the protonmotive force
- 25What are the two parts of the protonmotive force?1. Voltage gradient (more positive outside)
2. pH gradient (more acidic inside 7.2 vs. 7.9) - 26What does the protonmotive force power?ATP synthase
- 27What occurs when levels of ADP rise/ATP falls?Increased O2 uptake, increase oxi. phos.
Vice versa if ADP falls/ATP rises - 28What are inhibitors of oxidative phosphorylation?CN-
Carbon monoxide
Rotenone (inhibits complex 1)
Inhibit the activity of cytochrome - 29What do uncouplers do?Create channel bypassing ATP synthase to release energy as heat
- 30What are examples of uncouplers?Dinitrophenol
Thermogenin protein in brown adipose tissue - 31Summary of ATP synthesis2 from glycolysis
5 from 2xNADH from pyruvate dehydrogenase
2 from GTP from TCA
15 from 6xNADH from TCA
3 from 2XFADH2 from TCA
5/3 from NADH from glycolysis
Total 30/32
Informações
- Descrição
- pyruvate dehydrogenase rxn role of acety-CoA TCA cycle NADH/FADH2 Oxoloacetate AA/haem from TCA e- transport chain carriers pumping h+ ATP synthase ADP/ATP effect on oxi. phos Inhibitor/uncoupler
- Criado por
- Evian Chai
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