Q. A 6-month-old boy is brought to the pediatrician by his parents, who are concerned about his failure to thrive. Despite being fed regularly, the boy hasn't gained much weight and seems lethargic. Initial investigations show an elevated level of ammonia in his blood. The physician suspects a defect in the urea cycle. One of the critical steps in this cycle is the synthesis of carbamoyl phosphate. Considering the above information, where does the synthesis of carbamoyl phosphate occur?