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

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

Explanation

HMG-CoA reductase is the enzyme responsible for the rate-limiting step in the biosynthesis of cholesterol, converting HMG-CoA to mevalonate.

Mnemonic

HMG = Heart's Main Goal (to reduce cholesterol)

Source

Biochemistry by Jeremy M. Berg
Lipid Metabolism Biochemistry Cholesterol Biosynthesis Hard MEDICAL Confidence: high