Chapter 13, Problem 13.97EP

(a)

Interpretation Introduction

Interpretation: To indicate whether the statement “phosphorylated versions of ${\text{NAD}}^{+}/\text{NADH}$ are encountered in the PPP” relating to the pentose phosphate pathway (PPP) is true or false.

Concept introduction: The pentose phosphate pathway is a metabolic pathway in which NADPH, $\text{ribose 5}-\text{phosphate}$, and other sugar phosphates are produced from $\text{glucose 6}-\text{phosphate}$ and ${\text{NADP}}^{+}$.

Pentose phosphate pathway is a two-stage metabolic pathway. The first stage of phosphate pentose pathway is an oxidative stage and the second stage is a non-oxidative stage.

Nicotinamide adenine dinucleotide is associated with the redox reactions in metabolism. Its reduced form is NADH and oxidized form is ${\text{NAD}}^{+}$.

(b)

Interpretation Introduction

Interpretation: To indicate whether the statement “the initial reactant for the PPP is a pentose” relating to the pentose phosphate pathway (PPP) is true or false.

Concept introduction: The pentose phosphate pathway is defined as the metabolic pathway in which NADPH, $\text{ribose 5}-\text{phosphate}$, and other sugar phosphates are produced from $\text{glucose 6}-\text{phosphate}$ and ${\text{NADP}}^{+}$.

Pentose phosphate pathway is a two-stage metabolic pathway. The first stage of phosphate pentose pathway is an oxidative stage and the second stage is a non-oxidative stage.

A reactant is defined as the substance that is initially present in the chemical reaction and gets consumed to form a new substance.

(c)

Interpretation Introduction

Interpretation: To indicate whether the statement “the oxidative stage of the PPP precedes the non-oxidative stage of the PPP” relating to the pentose phosphate pathway (PPP) is true or false.

Concept introduction: The pentose phosphate pathway is defined as the metabolic pathway in which NADPH, $\text{ribose 5}-\text{phosphate}$, and other sugar phosphates are produced from $\text{glucose 6}-\text{phosphate}$ and ${\text{NADP}}^{+}$.

(d)

Interpretation Introduction

Interpretation: To indicate whether the statement “${\text{CO}}_2$ is a product of the first stage of the PPP” relating to the pentose phosphate pathway (PPP) is true or false.

Concept introduction: The pentose phosphate pathway is defined as the metabolic pathway in which NADPH, $\text{ribose 5}-\text{phosphate}$, and other sugar phosphates are produced from $\text{glucose 6}-\text{phosphate}$ and ${\text{NADP}}^{+}$.

Pentose phosphate pathway is a two-stage metabolic pathway. The first stage of phosphate pentose pathway is an oxidative stage and the second stage is a non-oxidative stage.

A product is defined as the substance that is formed after the completion of a chemical reaction.