This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Bio-Chemistry), Subject name: Biochemistry
Carbamoyl phosphate intermediates the synthesis of 
Select and explain. 
A. Urea, B. Urea & Pyrimidine, C. Uric acid, D. Ketone body
B: Urea & Pyrimidine
Answer: B: Urea & Pyrimidine 
Explanation: (B) Urea & Pyrimidine # Biosynthesis of urea begins with the condensation of CC>2, NHs and ATP to form carbamoyl phosphate, a reaction catalyzed by carbamoyl phosphate synthase I which is a mitochondrial enzyme, and rate limiting or pacemaker enzyme and the enzyme is active only in the presence of its allosteric activator N-acetylglutamate, which enhances the affinity of synthase for ATP.