Chapter 18, Problem 18.58AP

a.

Interpretation Introduction

Interpretation:

Role of ${\text{NAD}}^{+}$ and NADH in conversion of pyruvate to acetyl CoA 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 agents.

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.

b.

Interpretation Introduction

Interpretation:

Role of ${\text{NAD}}^{+}$ and NADH in conversion of pyruvate into lactate has to be determined.

Concept Introduction:

Refer to part a.

c.

Interpretation Introduction

Interpretation:

Role of ${\text{NAD}}^{+}$ and NADH in conversion of pyruvate to ethanol has to be determined.

Concept Introduction:

Refer to part a.