Chapter 23, Problem 23.77EP

(a)

Interpretation Introduction

Interpretation: To identify the coenzyme (${\text{NAD}}^{\text{+}}$ and FAD) that participates in the citric acid cycle reaction:

$\text{isocitrate}\to \alpha \text{-ketoglutarate}$

Concept introduction: Citric acid cycle is the third stage of the biochemical energy production process. The cycle includes the reactions in which the acetyl part of acetyl CoA is oxidized and leads to the formation of carbon dioxide and $\text{CoA-SH}$. An overview of the citric acid cycle is as follows:

Nicotinamide adenine dinucleotide $\left({\text{NAD}}^{+}\right)$ is employed as an oxidizing agent in various reactions like oxidation of secondary alcohol into a ketone. Its structure consists of three subunits: nicotinamide, ribose, and ADP.

(b)

Interpretation Introduction

Interpretation: To identify the coenzyme (${\text{NAD}}^{\text{+}}$ and FAD) that participates in the citric acid cycle reaction:

$\text{succinate}\to \text{fumarate}$

Concept introduction: Citric acid cycle is the third stage of the biochemical energy production process. The cycle includes the reactions in which the acetyl part of acetyl CoA is oxidized and leads to the formation of carbon dioxide and $\text{CoA-SH}$.

An overview of the citric acid cycle is as follows:

Flavin adenine dinucleotide exists in two forms: oxidized form $\left(\text{FAD}\right)$ and reduced form $\left({\text{FADH}}_2\right)$. The main function of flavin adenine dinucleotide is to act as an oxidizing agent and used by the cell in oxidation reactions like oxidation of fatty acid.