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22 Cards in this Set
- Front
- Back
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What is an alternate name of the TCA cycle? |
The Krebs Cycle |
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What is the TCA cycle? |
oxidation of acetyl CoA to CO2 and H20 |
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Where does the TCA cycle take place? |
the mitochondrial matrix |
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What is the function of the TCA cycle? |
energy trapping, synthesis of intermediates |
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What is the reaction prior to the TCA cycle? |
The link reaction CH3COCOOH+CoASH+NAD----->CH3COSCoA+CO2+NADH+H |
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What is the oxidation reaction of the TCA cycle? |
oxaloacetate+acetyl CoA---> citrate enzyme= citrate synthase |
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What is the isomerase reaction of the TCA cycle? |
Citrate---> isocitrate enzyme= aconitase |
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What is the first loss of CO2 in the TCA cycle? |
Isocitrate+NAD--->alpha-ketogluterate+NADH+H+CO2 enzyme=isocitrate dehydrogenase |
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What is the second loss of CO2 in the TCA cycle? |
alpha ketogluterate+CoA+NAD--->succinyl CoA+NADH+H+CO2 enzyme=alpha ketogluterate dehydrogenase |
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What happens in the trapping thioester bond energy as GTP? |
Succinyl CoA+GDP+Pi--->Succinate+GTP+CoA-SH enzyme= succinyl coA synthetase |
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What happens in the conversion of succinate to fumerate? |
succinate+FAD--->Fumerate+FADH2 enzyme= succinate dehydrogenase |
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what happens in the conversion of fumerate to maltate? |
fumerate+H20--->Maltate enzyme=fumerase |
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What happens in the conversion of maltate to oxaloacetate? |
Maltate+NAD--->ocaloacetate+H+NADH enzyme=maltate dehydrogenase |
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How is ATP generated in the TCA cycle? |
the reoxidation of NADH to NAD and FADH to FAD via the electron transport chain results in synthesis of ATP |
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What are the three irreversible key stages of the TCA cycle? |
3 enzyme steps= citrate synthase, isocitrate dehydrogenase, alpha ketogluterate dehydrogenase |
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Why are the 3 stages irreversible? |
This is due to the release of CO2 which is entropically favoured |
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Which three products are used in biosynthesis? |
oxaloactate alpha ketogluterate succinyl CoA |
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How is oxaloacetate used? |
transaminated to aspartate and then used to make other amino acids, purines and pyramidines |
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How is alpha ketogluterate used? |
converted to glutamate other amino acids |
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How is succinyl CoA used? |
made into haem |
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How is the TCA cycle topped up anapleoticly? |
pyruvate is converted to oxaloacetate by pyruvate carboxylase pyruvate is converted to matate by malic enzyme |
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How is glucose created from oxaloacetate? |
oxaloacetate is converted to phosphoenol pyruvate by PEP carboxylase and this is converted to glucose |
