This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Carbamoyl phosphate synthetase I is: 
Select and explain. 
A. Lysosolic enzyme, B. Cytosolic enzyme, C. Mitochondrial enzyme, D. All of the above
C: Mitochondrial enzyme
Answer: C: Mitochondrial enzyme 
Explanation: Mitochondrial carbamoyl phosphate synthetase I is an enzyme that catalyzes a reaction that produces carbamoyl phosphate.This enzyme catalyzes the reaction of ATP and bicarbonate to produce carbonyl phosphate and ADP. Carbonyl phosphate reacts with ammonia to give carbamateCytosolic carbamoyl phosphate synthetase II uses glutamine rather than ammonia as the nitrogen donor and functions in pyrimidine synthesis.