Question

Entry to the citric acid cycle involves the generation of acetyl CoA. The enzyme that catalyzes the production of acetyl CoA is _____. This enzyme is negatively regulated by _____ in a high-energy charge situation.

citrate synthase; ATP
pyruvate dehydrogenase; NADH
α-ketoglutarate dehydrogenase complex; ATP
α-ketoglutarate dehydrogenase complex; NADH

Answer 1

The correct answer is pyruvate dehydrogenase; NADH.

Step-by-step explanation:

Entry to the citric acid cycle involves the generation of acetyl CoA. The enzyme that catalyzes the production of acetyl CoA is pyruvate dehydrogenase. This enzyme is negatively regulated by NADH in a high-energy charge situation.

Acetyl CoA is obtained by the decarboxylation of pyruvate which is catalyzed by the pyruvate dehydrogenase complex. Later, the excess of NADH represents a feedback inhibition in the enzyme.