<prompt> The enzyme carbamoyl phosphate synthetase requires:MgCaKNone of the above  <response>: One molecule of ammonia condenses with CO2 in the presence of two molecules of ATP to form carbamoyl phosphate. The reaction is catalyzed by the mitochondrial enzyme carbamoyl phosphate synthetase-I CPS-I.Reference: Vasudevan 7th ed, pg 203 