Question

The cost of biosynthesizing fatty acids is expensive. how many NADPH are invested per round of fatty acid biosynthesis?

A) 1 NADPH
B) 2 NADPH
C) 3 NADPH
D) 4 NADPH

Answer 1

Two molecules of NADPH are invested per round of fatty acid biosynthesis: one for the reduction by 3-ketoacyl-ACP reductase and another for the reduction by enoyl-ACP reductase.

Step-by-step explanation:

The question relates to the biosynthesis of fatty acids, particularly the amount of NADPH consumed per cycle. During the fatty acid synthesis process, each round (or cycle) consumes two molecules of NADPH. One molecule is used during the conversion of acetoacetyl-S-ACP to 3-hydroxyacyl-S-ACP by the enzyme 3-ketoacyl-ACP reductase. A second NADPH molecule is involved in the conversion of enoyl-S-ACP to saturated acyl-S-ACP by the enzyme enoyl-ACP reductase.

Thus, the correct answer to the question of how many NADPH molecules are invested per round of fatty acid biosynthesis is B) 2 NADPH.