Chapter 25, Problem 25.19EP

(a)

Interpretation Introduction

Interpretation: To determine the step of glycerol metabolism in which ATP is consumed.

Concept introduction: Triacylglycerol mobilization is an ongoing process in which triacylglycerols that are stored in the adipose tissue are hydrolyzed. Fatty acids and glycerol are the products of triacylglycerol mobilization. The products are released into the bloodstream.

After entering the bloodstream, the glycerol travels to the kidneys or liver. The first stage of glycerol metabolism occurs in the liver or kidney. The first stage of glycerol metabolism is a two-step process. After the first stage, the remaining stages of glycerol metabolism are the same as glucose pathways. The overall equation for glycerol metabolism is as follows:

$\text{Glycerol}+\text{ATP}+{\text{NAD}}^{+}\to \text{Dihydroxyacetone phosphate}+\text{ADP}+\text{NADH}+{\text{H}}^{+}$

Adenosine triphosphate (ATP) is a triphosphate nucleotide that provide energy to carry out the metabolic processes in the living cells. It is converted either to adenosine monophosphate (AMP) or to adenosine diphosphate (ADP) after the consumption in the metabolic processes.

(b)

Interpretation Introduction

Interpretation: To determine the step of glycerol metabolism in which a phosphorylation reaction occurs.

Concept introduction: Triacylglycerol mobilization is an ongoing process in which triacylglycerols that are stored in the adipose tissue are hydrolyzed. Fatty acids and glycerol are the products of triacylglycerol mobilization. The products are released into the bloodstream.

After entering the bloodstream, the glycerol travels to the kidneys or liver. The first stage of glycerol metabolism occurs in the liver or kidney. The first stage of glycerol metabolism is a two-step process. After the first stage, the remaining stages of glycerol metabolism are the same as glucose pathways. The overall equation for glycerol metabolism is as follows:

$\text{Glycerol}+\text{ATP}+{\text{NAD}}^{+}\to \text{Dihydroxyacetone phosphate}+\text{ADP}+\text{NADH}+{\text{H}}^{+}$

In the phosphorylation reaction, a phosphoryl group $\left({\text{PO}}_3^{2-}\right)$ is transfer to an organic compound. Kinase enzymes, phosphate nucleotides are used for the transfer of the phosphoryl group.

(c)

Interpretation Introduction

Interpretation: To determine the step of glycerol metabolism in which dihydroxyacetone phosphate is produced.

Concept introduction: Triacylglycerol mobilization is an ongoing process in which triacylglycerols that are stored in the adipose tissue are hydrolyzed. Fatty acids and glycerol are the products of triacylglycerol mobilization. The products are released into the bloodstream.

After entering the bloodstream, the glycerol travels to the kidneys or liver. The first stage of glycerol metabolism occurs in the liver or kidney. The first stage of glycerol metabolism is a two-step process. After the first stage, the remaining stages of glycerol metabolism are the same as glucose pathways. The overall equation for glycerol metabolism is as follows:

$\text{Glycerol}+\text{ATP}+{\text{NAD}}^{+}\to \text{Dihydroxyacetone phosphate}+\text{ADP}+\text{NADH}+{\text{H}}^{+}$

(d)

Interpretation Introduction

Interpretation: To determine the step of glycerol metabolism in which glycerol kinase is active.

Concept introduction: Triacylglycerol mobilization is an ongoing process in which triacylglycerols that are stored in the adipose tissue are hydrolyzed. Fatty acids and glycerol are the products of triacylglycerol mobilization. The products are released into the bloodstream.

After entering the bloodstream, the glycerol travels to the kidneys or liver. The first stage of glycerol metabolism occurs in the liver or kidney. The first stage of glycerol metabolism is a two-step process. After the first stage, the remaining stages of glycerol metabolism are the same as glucose pathways. The overall equation for glycerol metabolism is as follows:

$\text{Glycerol}+\text{ATP}+{\text{NAD}}^{+}\to \text{Dihydroxyacetone phosphate}+\text{ADP}+\text{NADH}+{\text{H}}^{+}$

In the phosphorylation reaction, a phosphoryl group $\left({\text{PO}}_3^{2-}\right)$ is transfer to an organic compound. Kinase enzymes are used for the transfer of the phosphoryl group.