A 30carbon precursor formed during cholesterol biosynthesis

A 30-carbon precursor formed during cholesterol biosynthesis of the sterod nucleus is _____. _____ enzyme reaction limits the rate of biosynthesis of cholesterol from ______. Indicate the role of any cofactor/coenzyme that participates in the reaction in part b.______.

Solution

Answer:

a). Squalene.

Explanation:

Squalene is a natural 30-carbon organic compound originally obtained for commercial purposes primarily from shark liver oil although plant sources are now used as well, including amaranth seed, rice bran, wheat germ, and olives. Squalene is the biochemical precursor to the whole family of steroids.

2). 3-hydroxy-3-methylglutaryl-CoA reductase

Explanation:

Acetoacetyl-CoA condenses with another Acetyl-CoA molecule to form 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA). HMG-CoA is reduced to mevalonate by NADPH. HMG-CoA reductase is the rate-limiting step in cholesterol synthesis.

3). NAD

Explanation:

HMG-CoA reductase (3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, officially abbreviated HMGCR) is the rate-controlling enzyme (NADH-dependent & NADPH-dependent) of the mevalonate pathway, the metabolic pathway that produces cholesterol and other isoprenoids.