Carbamoyl phosphate synthetase I is:

Mitochondrial carbamoyl phosphate synthetase I is an enzyme that catalyzes a reaction that produces carbamoyl phosphate.This enzyme catalyzes the reaction of ATP and bicarbonate to produce carbonyl phosphate and ADP. Carbonyl phosphate reacts with ammonia to give carbamateCytosolic carbamoyl phosphate synthetase II uses glutamine rather than ammonia as the nitrogen donor and functions in pyrimidine synthesis.