Anaplerotic reactions are those that result in replenishing intermediates in the TCA cycle. Which of the following enzymes catalyzes an anaplerotic reaction?
A) citrate synthase
B) malate dehydrogenase
C) pyruvate carboxylase
D) pyruvate kinase
E) succinyl-CoA synthetase

Question

Anaplerotic reactions are those that result in replenishing intermediates in the TCA cycle. Which of the following enzymes catalyzes an anaplerotic reaction?
A) citrate synthase
B) malate dehydrogenase
C) pyruvate carboxylase
D) pyruvate kinase
E) succinyl-CoA synthetase

Quizplus · Accepted Answer

Pyruvate carboxylase catalyzes the conversion of pyruvate to oxaloacetate, replenishing TCA cycle intermediates, thus it is an anaplerotic reaction.  Pyruvate carboxylase catalyzes the carboxylation of pyruvate-forming oxaloacetate, which can then enter the TCA cycle (anaplerotic) keeping the cycle replenished.

Anaplerotic Reactions Are Those That Result in Replenishing Intermediates in the TCA