Like all biosynthetic reactions, synthesis of cholesterol requires the input of energy in the form of ATP. In addition, cholesterol biosynthesis is dependent upon input of cytoplasmic precursor carbon atoms in the form of acetyl-CoA. Which of the following enzymes, each of which plays a role in cholesterol synthesis, is most dependent upon ATP for maximal activity?
A) citrate synthase
B) 7-dehydrocholesterol reductase (DHCR7)
C) HMG-CoA reductase (HMGR)
D) malate dehydrogenase
E) pyruvate carboxylase

Question

Quizplus · Accepted Answer

The cytoplasmic acetyl-CoA required for de novo cholesterol biosynthesis is primarily derived from mitochondrial acetyl-CoA. The movement of acetyl-CoA from the mitochondria to the cytosol requires several enzymes including pyruvate carboxylase and citrate synthase. Pyruvate is the only one that is dependent upon ATP for activity.

Like All Biosynthetic Reactions, Synthesis of Cholesterol Requires the Input