<prompt> Carbamoyl group of carbamoyl phosphate is derived from ?AmmoniaCitrullineOrnithineArginosuccinate  <response>: Ans. is a i.e., Ammonia 1st reaction of urea cycle is synthesis of carbamoyl phosphate by condensation of ammonia NH4 and CO2.The carbamoyl group of carbomoyl phosphate is derived from NH4. and a bicarbonate ion.The reaction is energetically demanding two ATP and is catalyzed by carbomoyl phosphate synthase LCPS-I is allosterically activated by N-acetyl glutamate. 