Chapter 24, Problem 24.118EP

(a)

Interpretation Introduction

Interpretation: To indicate whether B vitamin niacin is involved in (1) glycolysis, (2) gluconeogenesis, (3) lactate fermentation, or (4) glycogenolysis as a cofactor.

Concept introduction: Vitamins are defined as the micronutrients that are needed in a small amount for the proper functioning of the metabolic activities in the organisms.

Cofactors are non-protein organic compounds that are used along with the enzymes and help to carry forward the reaction. Cofactors cannot perform on their own alone.

In the glycolysis metabolic pathway, a glucose molecule breaks down into two pyruvate molecules. In gluconeogenesis process, glucose is produced from non-carbohydrate substances. Glycogenolysis is the metabolic pathway that converts glycogen to $\text{glucose 6}-\text{phosphate}$.

In the absence of oxygen, pyruvate is converted to lactate by lactate dehydrogenase enzymes in the human body. In this reaction, NADH is oxidized to ${\text{NAD}}^{+}$. This anaerobic reduction is called lactate fermentation.

Niacin $\left({\text{as NADH, NAD}}^{+}\right)$ , thiamin (as TPP), riboflavin (as FAD),  pantothenic acid $\left(\text{as CoA}\right)$, biotin, and ${\text{vitamin B}}_6$ (as PLP) are the different B vitamins involved in the reactions associated with the metabolism of carbohydrates.

(b)

Interpretation Introduction

Interpretation: To indicate B vitamin biotin is involved in (1) glycolysis, (2) gluconeogenesis, (3) lactate fermentation, or (4) glycogenolysis as a cofactor.

Concept introduction: Vitamins are defined as the micronutrients that are needed in a small amount for the proper functioning of the metabolic activities in the organisms.

Cofactors are non-protein organic compounds that are used along with the enzymes and help to carry forward the reaction. Cofactors cannot perform on their own alone.

In the glycolysis metabolic pathway, a glucose molecule breaks down into two pyruvate molecules. In gluconeogenesis process, glucose is produced from non-carbohydrate substances. Glycogenolysis is the metabolic pathway that converts glycogen to $\text{glucose 6}-\text{phosphate}$.

In the absence of oxygen, pyruvate is converted to lactate by lactate dehydrogenase enzymes in the human body. In this reaction, NADH is oxidized to ${\text{NAD}}^{+}$. This anaerobic reduction is called lactate fermentation.

Niacin $\left({\text{as NADH, NAD}}^{+}\right)$ , thiamin (as TPP), riboflavin (as FAD),  pantothenic acid $\left(\text{as CoA}\right)$, biotin, and ${\text{vitamin B}}_6$ (as PLP) are the different B vitamins involved in the reactions associated with the metabolism of carbohydrates.

(c)

Interpretation Introduction

Interpretation: To indicate B vitamin folate is involved in (1) glycolysis, (2) gluconeogenesis, (3) lactate fermentation, or (4) glycogenolysis as a cofactor.

Concept introduction: Vitamins are defined as the micronutrients that are needed in a small amount for the proper functioning of the metabolic activities in the organisms.

Cofactors are non-protein organic compounds that are used along with the enzymes and help to carry forward the reaction. Cofactors cannot perform on their own alone.

In the glycolysis metabolic pathway, a glucose molecule breaks down into two pyruvate molecules. In gluconeogenesis process, glucose is produced from non-carbohydrate substances. Glycogenolysis is the metabolic pathway that converts glycogen to $\text{glucose 6}-\text{phosphate}$.

In the absence of oxygen, pyruvate is converted to lactate by lactate dehydrogenase enzymes in the human body. In this reaction, NADH is oxidized to ${\text{NAD}}^{+}$. This anaerobic reduction is called lactate fermentation.

(d)

Interpretation Introduction

Interpretation: To indicate ${\text{vitamin B}}_{12}$ is involved in (1) glycolysis, (2) gluconeogenesis, (3) lactate fermentation, or (4) glycogenolysis as a cofactor.

Concept introduction: Vitamins are defined as the micronutrients that are needed in a small amount for the proper functioning of the metabolic activities in the organisms.

Cofactors are non-protein organic compounds that are used along with the enzymes and help to carry forward the reaction. Cofactors cannot perform on their own alone.

In the glycolysis metabolic pathway, a glucose molecule breaks down into two pyruvate molecules. In gluconeogenesis process, glucose is produced from non-carbohydrate substances. Glycogenolysis is the metabolic pathway that converts glycogen to $\text{glucose 6}-\text{phosphate}$.

In the absence of oxygen, pyruvate is converted to lactate by lactate dehydrogenase enzymes in the human body. In this reaction, NADH is oxidized to ${\text{NAD}}^{+}$. This anaerobic reduction is called lactate fermentation.