The Vitamin That is Part of the Coenzyme NAD Is

Question

The vitamin that is part of the coenzyme NAD is
A) thiamine.
B) riboflavin.
C) niacin.
D) folic acid (folate).
E) cobalamin.

Accepted Answer

NAD (nicotinamide adenine dinucleotide) is composed of nicotinamide, a derivative of niacin (also known as vitamin B3), and adenine dinucleotide. Therefore, niacin is the vitamin that is part of the coenzyme NAD. Thiamine (choice A) is part of the coenzyme thiamine pyrophosphate (TPP), riboflavin (choice B) is part of the coenzymes flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), folic acid (folate) (choice D) is a precursor to coenzymes involved in one-carbon metabolism, and cobalamin (choice E) is part of the coenzymes methylcobalamin and adenosylcobalamin.