Which enzyme is responsible for catalyzing the rate-limiting step in the biosynthesis of cholesterol?

A HMG-CoA synthase
B HMG-CoA reductase ✓
C Acetyl-CoA carboxylase
D Fatty acid synthase

Explanation

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

Mnemonic

HMG-CoA reductase = Heart of Mevalonate Generation, reduces HMG-CoA

Source

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