Q. A 27-year-old woman presents to the emergency department with increasing confusion and drowsiness over the last two days. She has a history of alcoholism and was recently diagnosed with cirrhosis. A blood test shows elevated ammonia levels. The attending physician explains to the medical students present that liver damage can impair the detoxification of ammonia through the urea cycle, particularly at the initial stage of carbamoyl phosphate synthesis. Which substrates are necessary for the production of carbamoyl phosphate in the urea cycle?