Chapter 23, Problem 23.99EP

(a)

Interpretation Introduction

Interpretation: To classify NADH as (1) a reactant in the CAC, (2) a reactant in the ETC, or (3) a reactant in both the CAC and the ETC.

Concept introduction: Common metabolic pathway is the total sum of metabolic reactions that occur in stage third and fourth of the biochemical process or it is defined as the total sum of reactions that occur in the citric acid cycle and electron transport chain and oxidative phosphorylation.

These stages are included in the common metabolic pathway because the reactions in these stages are the same for different kinds of food.

The 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 $\text{CoA-SH}$.

Electron transport chain is a sequence of biochemical reactions in which electrons and hydrogen atoms from the citric acid cycle are transferred to various intermediate carriers and finally reacts with molecular oxygen to form a water molecule.

(b)

Interpretation Introduction

Interpretation: To classify ${\text{O}}_{\text{2}}$ as (1) a reactant in the CAC, (2) a reactant in the ETC, or (3) a reactant in both the CAC and the ETC.

Concept introduction: Common metabolic pathway is the total sum of metabolic reactions that occur in stage third and fourth of the biochemical process or it is defined as the total sum of reactions that occur in the citric acid cycle and electron transport chain and oxidative phosphorylation.

These stages are included in the common metabolic pathway because the reactions in these stages are the same for different kinds of food.

The 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 $\text{CoA-SH}$.

Electron transport chain is a sequence of biochemical reactions in which electrons and hydrogen atoms from the citric acid cycle are transferred to various intermediate carriers and finally reacts with molecular oxygen to form a water molecule.

(c)

Interpretation Introduction

Interpretation: To classify fumarate as (1) a reactant in the CAC, (2) a reactant in the ETC, or (3) a reactant in both the CAC and the ETC.

Concept introduction: Common metabolic pathway is the total sum of metabolic reactions that occur in stage third and fourth of the biochemical process or it is defined as the total sum of reactions that occur in the citric acid cycle and electron transport chain and oxidative phosphorylation.

These stages are included in the common metabolic pathway because the reactions in these stages are the same for different kinds of food.

The 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 $\text{CoA-SH}$.

Electron transport chain is a sequence of biochemical reactions in which electrons and hydrogen atoms from the citric acid cycle are transferred to various intermediate carriers and finally reacts with molecular oxygen to form a water molecule.

(d)

Interpretation Introduction

Interpretation: To classify $\text{cytochrome}\text{a}$ as (1) a reactant in the CAC, (2) a reactant in the ETC, or (3) a reactant in both the CAC and the ETC.

Concept introduction: Common metabolic pathway is the total sum of metabolic reactions that occur in stage third and fourth of the biochemical process or it is defined as the total sum of reactions that occur in the citric acid cycle and electron transport chain and oxidative phosphorylation.

These stages are included in the common metabolic pathway because the reactions in these stages are the same for different kinds of food.

The 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 $\text{CoA-SH}$.

Electron transport chain is a sequence of biochemical reactions in which electrons and hydrogen atoms from the citric acid cycle are transferred to various intermediate carriers and finally reacts with molecular oxygen to form a water molecule.