a Arrange the following enzyme activities in order that they

(a) Arrange the following enzyme activities in order that they first appear in the biosynthesis of stearoyl CoA in the cytosol of the liver cell. (A) Acetyl CoA Carboxylase (B) Acetyl CoA Transferase (C) beta-hydroxyacyl ACP-dehydratase (D) beta-ketoacyl ACP reductase (E) beta-hydroxyacyl CoA-dehydratase (F) beta-ketoacyl CoA reductase (G) Elongase (H) Enoyl ACP reductase (I) Enoyl-CoA reductase (J) Fatty Acyl CoA Synthetase (K) Malonyl CoA Transferase (L) Thioesterase (b) How many ATP equivalents and NADPHs are required to synthesize arachidate from cytostolic acetyl CoA?

Solution

a.

Acetyl CoA transferase

Malonyl CoA transferase

Acetyl CoA carboxylase

b-ketoacyl CoA reductase

b-ketoacyl ACP reductase

b-hydroxyacyl CoA dehydratase

b-hydroxyacyl ACP dehydratase

Enoyl CoA reductase

Enoyl ACP reductase

Thioesterase

b.Arachidate is a 20 C fatty acid. It requires 9 ATP to charge acetyl CoA to malonyl CoA. 18 NADPH are requied for the reduction of C=C and C=O bonds.