Urea cycle in liver helps in conversion of excess of amino acids into urea. It takes place in five major steps.
1. The amino acids undergo deamination in liver.
2. The amino acids are broken down into nitrogen-containing amine groups (NH
2
) which can be toxic to cells by the process of deamination.
3. The amine group produced during the deamination converts into ammonium ions and enters urea cycle.
4. The urea cycle converts highly toxic ammonia to urea for excretion.
5. It starts with the condensation of ammonium ion with bicarbonate ion which results the formation of carbamoyl phosphate in the presence of enzyme carbamoyl phosphate synthase.
6. Carbamoyl phosphate combines with ornithine to form citrulline in presence of enzyme citrulline synthase or ornithine transcarbamoylase.
7. Citrulline diffuses into the cytosol.
8. Citrulline combines with the amino acid aspartate and argininosuccinate catalyzed by the enzyme argininosuccinate synthase.
9. The enzyme argininosuccinase acts reversibly to cleave argininosuccinate into arginine and fumarate.
10. Arginine is lysed into ornithine and urea under the influence of the enzyme arginase.
11. The urea formed in liver is transported to kidney through circulation and finally gets excreted.
Answers & Comments
Answer:
true
please mark me as brain list
Answer:
true
Explanation:
Urea cycle in liver helps in conversion of excess of amino acids into urea. It takes place in five major steps.
1. The amino acids undergo deamination in liver.
2. The amino acids are broken down into nitrogen-containing amine groups (NH
2
) which can be toxic to cells by the process of deamination.
3. The amine group produced during the deamination converts into ammonium ions and enters urea cycle.
4. The urea cycle converts highly toxic ammonia to urea for excretion.
5. It starts with the condensation of ammonium ion with bicarbonate ion which results the formation of carbamoyl phosphate in the presence of enzyme carbamoyl phosphate synthase.
6. Carbamoyl phosphate combines with ornithine to form citrulline in presence of enzyme citrulline synthase or ornithine transcarbamoylase.
7. Citrulline diffuses into the cytosol.
8. Citrulline combines with the amino acid aspartate and argininosuccinate catalyzed by the enzyme argininosuccinate synthase.
9. The enzyme argininosuccinase acts reversibly to cleave argininosuccinate into arginine and fumarate.
10. Arginine is lysed into ornithine and urea under the influence of the enzyme arginase.
11. The urea formed in liver is transported to kidney through circulation and finally gets excreted.