Carbamoyl phosphate is an anion of biochemical significance. In land-dwelling animals it is an intermediary metabolite participating in the nitrogen disposal through in the urea cycle and the synthesis of pyrimidines.
It is produced from bicarbonate, ammonia (derived from glutamine), and phosphate (from ATP). The synthesis is catalysed by the enzyme carbamoyl phosphate synthetase, as follows:
- HCO3− + ATP → ADP + HO–C(O)–OPO32− (carboxyl phosphate)
- HO–C(O)–OPO32− + NH3 + OH− → HPO42− + −O–C(O)NH2 + H2O
- −O–C(O)NH2 + ATP → ADP + H2NC(O)OPO32−