Which enzyme is responsible for catalyzing the rate-limiting step in the biosynthesis of cholesterol, specifically the conversion of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) to mevalonate?

A HMG-CoA synthase
B HMG-CoA reductase ✓
C Mevalonate kinase
D Phosphomevalonate kinase

Explanation

HMG-CoA reductase is the enzyme that catalyzes the conversion of HMG-CoA to mevalonate, a critical and rate-limiting step in the biosynthesis of cholesterol.

Source

Biochemistry by Stryer
Lipid Metabolism Biochemistry Cholesterol Biosynthesis Hard MEDICAL Confidence: high