<prompt> All of the following regarding urea cycle is true, except:On consumption of high amount of proteins, excess urea is formedSynthesis of argininosuccinate consumes energyRate limiting enzyme is ornithine transcarbamoylaseOne nitrogen of urea comes from aspartate  <response>: Carbamoyl phosphate synthase I, the rate-limiting enzyme of the urea cycle, is active only in the presence of N-acetylglutamate, an allosteric activator that enhances the affinity of the synthase for ATP. 