When a molecule of nad+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a hydrogen ion) the molecule becomes:

a) redoxed. b) hydrogenated. c) oxidized. d) reduced. e) a reducing agent.

The correct answer is- D) reduced

Explanation:

If a molecule loses hydrogen than it is said to be oxidized and if a molecule gain hydrogen than that molecule is said to be reduced. NAD+ is a very important coenzyme that accepts and loos hydrogen during the metabolic process.

As after accepting hydrogen, the coenzyme gets reduced and then it helps in feeding electron in the electron transport chain which is required to generate ATP through oxidative phosphorylation. So by doing this the NADH again gets oxidized to NAD+. Therefore the correct answer is D.

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