Chapter 26, Problem 26.81EP

(a)

Interpretation Introduction

Interpretation: To classify leucine as (1) ketogenic, (2) glucogenic, or (3) both ketogenic and glucogenic.

Concept introduction: Genicity of an amino acid is defined as whether the carbon skeleton degradation product of an amino acid can produce glucose or ketone bodies or not.

An amino acid is known as a glucogenic amino acid if its carbon-containing degradation product can be used to produce glucose. An amino acid is known as a ketogenic amino acid if its carbon-containing degradation product can be used to produce ketone bodies.

There are 20 standard amino acids. Each amino acid has a different carbon skeleton and has a different degradation pathway for its carbon skeleton. The degradation pathways for different amino acids merge in between and result in the formation of only 7 products. The 7 products are $\text{α-ketoglutarate}$, $\text{succinyl CoA}$, fumarate, oxaloacetate, pyruvate, $\text{acetyl CoA}$ and $\text{acetoacetyl CoA}$.

(b)

Interpretation Introduction

Interpretation: To classify isoleucine as (1) ketogenic, (2) glucogenic, or (3) both ketogenic and glucogenic.

Concept introduction: Genicity of an amino acid is defined as whether the carbon skeleton degradation product of an amino acid can produce glucose or ketone bodies or not.

An amino acid is known as a glucogenic amino acid if its carbon-containing degradation product can be used to produce glucose. An amino acid is known as a ketogenic amino acid if its carbon-containing degradation product can be used to produce ketone bodies.

There are 20 standard amino acids. Each amino acid has a different carbon skeleton and has a different degradation pathway for its carbon skeleton. The degradation pathways for different amino acids merge in between and result in the formation of only 7 products. The 7 products are $\text{α-ketoglutarate}$, $\text{succinyl CoA}$, fumarate, oxaloacetate, pyruvate, $\text{acetyl CoA}$ and $\text{acetoacetyl CoA}$.

(c)

Interpretation Introduction

Interpretation: To classify aspartate as (1) ketogenic, (2) glucogenic, or (3) both ketogenic and glucogenic.

Concept introduction: Genicity of an amino acid is defined as whether the carbon skeleton degradation product of an amino acid can produce glucose or ketone bodies or not.

An amino acid is known as a glucogenic amino acid if its carbon-containing degradation product can be used to produce glucose. An amino acid is known as a ketogenic amino acid if its carbon-containing degradation product can be used to produce ketone bodies.

There are 20 standard amino acids. Each amino acid has a different carbon skeleton and has a different degradation pathway for its carbon skeleton. The degradation pathways for different amino acids merge in between and result in the formation of only 7 products. The 7 products are $\text{α-ketoglutarate}$, $\text{succinyl CoA}$, fumarate, oxaloacetate, pyruvate, $\text{acetyl CoA}$ and $\text{acetoacetyl CoA}$.

(d)

Interpretation Introduction

Interpretation: To classify arginine as (1) ketogenic, (2) glucogenic, or (3) both ketogenic and glucogenic.

Concept introduction: Genicity of an amino acid is defined as whether the carbon skeleton degradation product of an amino acid can produce glucose or ketone bodies or not.

An amino acid is known as a glucogenic amino acid if its carbon-containing degradation product can be used to produce glucose. An amino acid is known as a ketogenic amino acid if its carbon-containing degradation product can be used to produce ketone bodies.

There are 20 standard amino acids. Each amino acid has a different carbon skeleton and has a different degradation pathway for its carbon skeleton. The degradation pathways for different amino acids merge in between and result in the formation of only 7 products. The 7 products are $\text{α-ketoglutarate}$, $\text{succinyl CoA}$, fumarate, oxaloacetate, pyruvate, $\text{acetyl CoA}$ and $\text{acetoacetyl CoA}$.