2. Nitrogen Excretion and the Urea Cycle

Urea Is Produced from Ammonia in Five Enzymatic Steps

The Citric Acid and Urea Cycles Can Be Linked

The Activity of the Urea Cycle Is Regulated at Two Levels

BOX 18-1 Assays for Tissue Damage

Pathway Interconnections Reduce the Energetic Cost of Urea Synthesis

Genetic Defects in the Urea Cycle Can Be Life-Threatening