KETOGENESIS

KETOGENESIS

• The process of biosynthesis of ketone bodies is known as ketogenesis.

steps

• The steps are:

(a) Two molecules of acetyl CoA are condensed to form acetoacetyl CoA; the reaction is catalyzed by the Enzyme thiolase.

(b) Acetoacetyl CoA condenses with another molecule of acetyl CoA to produce HMG-CoA (3-hydroxy 3 Methyl glutaryl CoA).

- HMG CoA synthase, the rate-limiting enzyme, catalyzes the reaction.

(c) HMG CoA cleaves and produces acetoacetate and acetyl CoA by HMG COA lyase.

(d) A small fraction of acetoacetate undergoes spontaneous decarboxylation and produce acetone.

(e) Acetoacetate is reduced by NADH to form B-hydroxybutyrate by the enzyme B-hydroxybutyrate Dehydrogenase.