2 ATP + NH4+ + HCO3- => 2 ADP + orthophosphate + carbamoyl phosphate 2 ATP + NH4+ + HCO3- => 2 ADP + orthophosphate + carbamoyl phosphate [mitochondrial] At the beginning of this reaction, 1 molecule of 'NH4+', 1 molecule of 'HCO3-', and 1 molecule of 'ATP' are present. At the end of this reaction, 1 molecule of 'Carbamoyl phosphate', 1 molecule of 'ADP', and 1 molecule of 'Orthophosphate' are present.<br><br> This reaction takes place in the 'mitochondrial matrix' and is mediated by the 'carbamoyl-phosphate synthase (ammonia) activity' of 'carbamoyl-phosphate synthetase I dimer'.<br> Authored: D'Eustachio, P, 2003-06-24 00:00:00 EC Number: 6.3.4.16 Edited: D'Eustachio, P, 2003-06-24 00:00:00 Pubmed6249820 Reactome Database ID Release 4370555 Reactome, http://www.reactome.org ReactomeREACT_1701 has a Stoichiometric coefficient of 2