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Human Function- Exam 4 Material > TCA Cycle > Flashcards

Flashcards in TCA Cycle Deck (17):
1

What is citrate from the TCA cycle used for?

fatty acid and sterol synthesis

2

what is alpha ketogluterate from the TCA cycle used for?

amino acid synthesis (neurotransmitters)

3

what is succinyl CoA from the TCA cycle used for?

heme synthesis

4

what is malate from the TCA cycle used for?

gluconeogenesis

5

what is oxaloacetate from the TCA cycle used for?

amino acid synthesis

6

what happens to the TCA cycle when intermediates are removed?

slows down because there is no oxaloacetate

7

What is an anapleurotic reaction?

reaction that returns intermediates to the TCA cycle

 

8

what is the most important anapleurotic reaction?

pyruvate carboxylase- conversion of pyruvate to oxaloacetate when Acetyl-CoA accumulates (means there is no oxaloacetate to react with Acetyl-CoA--> triggers conversion of pyruvate to oxaloacetate)

9

what is the role of pyruvate dehydroxylase?

convert pyruvate to oxaloacetate when acetyl-CoA builds up

10

where is pyruvate carboxylase activity highest?

liver and neuron mitochondria

11

what are the steps of pyruvate carboxylase reaction?

ATP + HCO3- + pyruvate (pyruvate carboxylase)--> oxaloacetate

pyruvate has 3 carbons, oxaloacetate has 4

extra carbon comes from HCO3-

 

12

what is the key regulated step of the TCA cylce?

isocitrate dehydrogenase

13

how is the isocitrate dehydrogenase reaction regulated?

activated by ADPregulated by ATP/ADP ratio

inhibited by ATP

 

 

14

what happens when the TCA cycle is inhibited at the key regulatory step?

citrate leaves the TCA cycle for other uses

15

what does loss of citrate require for the TCA cycle to continue?

anapleurotic reaction to replenish citrate to replenish oxaloacetate (pyruvate carboxylase reaction)

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