Chapter 18.3, Problem 18.5P

a.

Interpretation Introduction

Interpretation:

Classification of reaction below into oxidation and reduction has to be determined. Also, whether ${\text{NAD}}^{+}$ or NADH is used in completion of reaction below has to be determined.

Concept Introduction:

In metabolic pathways, many reactions involve coenzymes. These coenzymes are involved in oxidation and reduction reactions and can serve as oxidizing and reducing agent.

Oxidizing agent reduces to complete oxidation reaction while reducing agent oxidizes to complete reduction reaction.

More convenient way to spot oxidation and reduction reaction is from transfer of ${\text{H}}^{+}$ and ${\text{e}}^{-}$. If coenzyme gains ${\text{H}}^{+}$ and ${\text{e}}^{-}$ then it termed as reduced form and if coenzyme loses ${\text{H}}^{+}$ and ${\text{e}}^{-}$ then it termed as oxidized form.

Coenzyme ${\text{NAD}}^{+}$ is oxidized form of nicotinamide adenine dinucleotide. The reduced form of ${\text{NAD}}^{+}$ contains one hydride anion that is a hydrogen atom with 2 electrons that is NADH.

b.

Interpretation Introduction

Interpretation:

Classification of reaction below into oxidation and reduction has to be determined. Also, whether ${\text{NAD}}^{+}$ or NADH is used in completion of reaction below has to be determined.

Concept Introduction:

Refer to part a.