All of the following regarding urea cycle is true, except:
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.
On consumption  of high amount of proteins, excess urea is formed
Synthesis of argininosuccinate consumes energy
Rate limiting enzyme is ornithine transcarbamoylase
One nitrogen of urea comes from aspartate