Ornithine Cycle

Chapter Homeostasis : Ornithine Cycle

• NH3 combine with CO2 & H2O to form carbomoyl phosphate.
• Carbomoyl phosphate react with ornithine to form citrulline. This process occurs in matrix of mitochondria in liver cells.
• Citrulline react with aspartate to form argininosuccinate.
• Argininosuccinate breaks down to form fumarate & arginine. Fumarate enters Krebs Cycle.
• Arginine is hydrolysed by H2O to form urea & ornithine.
• Ornithine is released & reused.
• Urea is carried to the kidneys to be excreted in urine.