Chapter 26, Problem 14TYR

Summary Introduction

Introduction:

Protein catabolism occurs in prolonged fasting; it takes place when the fats and carbohydrates are not present in the body for energy production. Carbohydrates and fats have protein-sparing effects. In the absence of fats and carbohydrates, protein is used as the energy source; thus, proteins produce carbon skeleton for the gluconeogenesis and ammonia for excretion. This ammonia is toxic, so that it is excreted as urea by the kidney.