This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
Carbamoyl phosphate synthase I is used in 
Select and explain. 
A. Purine synthesis, B. Pyrimidine synthesis, C. Urea cycle, D. Uronic acid pathway
C: Urea cycle
Answer: C: Urea cycle 
Explanation: Carbamoyl phosphate synthase 1 conve CO2 + NH4 to Carvomyl phosphate Ref-Harpers illustrated biochemistry 30/e p680