Question

In ureotelic animals, urea is formed by

• A. Coris cycle
• B. Krebs cycle
• C. Ornithine cycle
• D. EMP pathway

Answer 1

The correct option is C Ornithine cycle

In ureotelic animals, urea is formed by Ornithine cycle. It helps in conversion of excess of amino acids into urea in the liver. It takes place in five major steps. The extra proteins in the body are degraded by the process of deamination where the NH${}_2$ group is removed and it is converted into ammonium ions in the liver. The ammonium ions enter urea cycle and combines with carbon dioxide and get converted into urea. The urea formed in liver is transported to kidney through circulation and finally gets excreted. So, the correct answer is 'Ornithine cycle'