Chapter 24, Problem 24.76EP

(a)

Interpretation Introduction

Interpretation: To identify the number of “common” steps in the gluconeogenesis and glycolysis processes in which the reactants/products are the reverse of each other and the enzyme is same.

Concept introduction: Glycolysis metabolic pathway is a ten-step enzyme catalyzed pathway in which a glucose molecule is converted to two pyruvate molecules. ATP and NADH-reduced coenzymes are produced along with pyruvate. The net overall equation for glycolysis is as follows:

$\text{Glucose}+2\text{ADP}+2{\text{P}}_{\text{i}}+2{\text{NAD}}^{+}\to 2\text{pyruvate}+2\text{NADH}+2\text{ATP}+2{\text{H}}^{+}+2{\text{H}}_2\text{O}$

In the gluconeogenesis pathway, glucose is produced from non-carbohydrate substances. The net overall equation for gluconeogenesis is as follows:

$2\text{pyruvate}+2\text{NADH}+4\text{ATP}+2\text{GTP}+2{\text{H}}_2\text{O}\to \text{Glucose}+4\text{ADP}+2\text{GDP}+6{\text{P}}_{\text{i}}+2{\text{NAD}}^{+}$

An overview of the pathways of glycolysis and gluconeogenesis is as follows:

(b)

Interpretation Introduction

Interpretation: To identify the number of “common” steps in the gluconeogenesis and glycolysis processes in which the reactants/products are the reverse of each other and the enzyme is different.

Concept introduction: Glycolysis metabolic pathway is a ten-step enzyme catalyzed pathway in which a glucose molecule is converted to two pyruvate molecules. ATP and NADH-reduced coenzymes are produced along with pyruvate. The net overall equation for glycolysis is as follows:

$\text{Glucose}+2\text{ADP}+2{\text{P}}_{\text{i}}+2{\text{NAD}}^{+}\to 2\text{pyruvate}+2\text{NADH}+2\text{ATP}+2{\text{H}}^{+}+2{\text{H}}_2\text{O}$

In the gluconeogenesis pathway, glucose is produced from non-carbohydrate substances. The net overall equation for gluconeogenesis is as follows:

$2\text{pyruvate}+2\text{NADH}+4\text{ATP}+2\text{GTP}+2{\text{H}}_2\text{O}\to \text{Glucose}+4\text{ADP}+2\text{GDP}+6{\text{P}}_{\text{i}}+2{\text{NAD}}^{+}$

An overview of the pathways of glycolysis and gluconeogenesis is as follows: