Citric Acid Cycle

Question 1

How do the 3 macro-nutrients produce acetyl-CoA?

Answer 1

Glucose goes through glycolysis→pyruvate→Acetyl CoA
Fatty acids go through beta-oxidation to Acetyl CoA
Amino acids go through transamination to Acetyl CoA

Question 2

Which 3 stages of the citric acid cycle are not reversible?

Answer 2

Citrate synbthase
Isocitrate dehydrogenase
alpha-ketoglutarate dehydrogenase

Question 3

What feedback inhibition is there for citrate synthase?

Answer 3

ATP, NADH, Succinyl-CoA

Question 4

What feedback is there for isocitrate dehydrogenase?

Answer 4

ADP activates

ATP and NADH inhibit

Question 5

What feedback is there for alpha-ketoglutarate dehydrogenase

Answer 5

NADH and Succinyl-CoA inhibit

Question 6

Which stages can pyruvate ‘top up’ the TCA cycle?

Answer 6

At oxaloacetate, allows glucose to be made from converting oxaloacetate→ phosphoenol pyruvate→ glucose
At malate