Which of the Following is the Reducing Agent in the Saturation

Question

Which of the following is the reducing agent in the saturation step of polyketide biosynthesis?
A) NADH
B) NADPH
C) ferredoxin
D) H2
E) O2

Accepted Answer

In the saturation step of polyketide biosynthesis, a keto group is reduced to an alcohol group. This reduction is catalyzed by a ketoreductase enzyme, which requires a reducing agent such as NADPH to donate a hydride ion for the reaction. Therefore, NADPH is the reducing agent in the saturation step.