Chapter 15, Problem 15.64EP

(a)

Interpretation Introduction

Interpretation: To identify whether carbamoyl phosphate or fumarate enters the urea cycle first.

Concept introduction: Urea cycle is a cyclic biochemical pathway that involves the production of urea using ammonium ions and aspartate molecules as nitrogen sources. It converts toxic ammonium ion to urea which is then excreted from the body in urine. The urea cycle is as follows:

(b)

Interpretation Introduction

Interpretation: To identify whether argininosuccinate or arginine enters the urea cycle first.

Concept introduction: Urea cycle is a cyclic biochemical pathway that involves the production of urea using ammonium ions and aspartate molecules as nitrogen sources. It converts toxic ammonium ion to urea which is then excreted from the body in urine. The urea cycle is as follows:

(c)

Interpretation Introduction

Interpretation: To identify whether ornithine or aspartate enters the urea cycle first.

Concept introduction: Urea cycle is a cyclic biochemical pathway that involves the production of urea using ammonium ions and aspartate molecules as nitrogen sources. It converts toxic ammonium ion to urea which is then excreted from the body in urine. The urea cycle is as follows:

(d)

Interpretation Introduction

Interpretation: To identify whether citrulline or ATP enters the urea cycle first.

Concept introduction: Urea cycle is a cyclic biochemical pathway that involves the production of urea using ammonium ions and aspartate molecules as nitrogen sources. It converts toxic ammonium ion to urea which is then excreted from the body in urine. The urea cycle is as follows: