<diacritize> Reactions of the urea cycle Step Awon ibase Awon esi Catalyzed by Location 1 NH3 HCO3- 2ATP carbamoyl phosphate 2ADP Pi CPS1 mitochondria 2 carbamoyl phosphate ornithine citrulline Pi OTC mitochondria 3 citrulline aspartate ATP argininosuccinate AMP PPi ASS cytosol 4 argininosuccinate Arg fumarate ASL cytosol 5 Arg H2O ornithine urea ARG1 cytosol <yor>Reactions of the urea cycle Step Àwọn ìbáṣe Àwọn èsì Catalyzed by Location 1 NH3 HCO3 2ATP carbamoyl phosphate 2ADP Pi CPS1 mitochondria 2 carbamoyl phosphate ornithine citrulline Pi OTC mitochondria 3 citrulline aspartate ATP argininosuccinate AMP PPi ASS cytosol 4 argininosuccinate Arg fumarate ASL cytosol 5 Arg H2O ornithine urea ARG1 cytosol 