Question

The committed and regulated step of cholesterol synthesis is the enzyme __________ which is an important target for a class of drugs called statins that can dramatically reduce circulating blood cholesterol and profoundhy reduce the incidence of heart attacks and stroke.

a) HMG-CoA synthase
b) HMG-CoA reductase
c) Acetyl-CoA acetyltransferase
d) Squalene synthase
e) Dehydrocholesterol reductase

Answer 1

b) HMG-CoA reductase

Step-by-step explanation:

HMG-CoA reductase (or 3-hydroxy-3-methyl-glutaryl-CoA reductase or HMGR) is an enzyme which plays a very important role in cholesterol biosynthesis pathway known as mevalonate pathway. HMG-CoA reductase catalyzes the conversion of HMG-CoA into mevalonic acid which is also a rate limiting step of cholesterol biosynthesis pathway. Once mevalonic acid is synthesized, it can be further converted into cholesterol. But, statins are a class of drugs which inhibit HMG-CoA reductase thereby blocking cholesterol biosynthesis.