CPS1 (Carbamoyl-phosphate synthase 1): CPS1 is a key enzyme in the urea cycle that plays a vital role in detoxifying ammonia in the body. It catalyses the formation of carbamoyl phosphate from ammonia and bicarbonate, initiating the process of urea synthesis in the liver. The urea cycle is essential for removing excess nitrogen produced from the breakdown of proteins and amino acids, preventing the toxic accumulation of ammonia in the bloodstream. CPS1 activity is carefully regulated to maintain nitrogen balance and prevent hyperammonaemia, a condition associated with neurological damage and other serious complications.