Where is CPS I located and what is its role?

Carbamoyl phosphate synthetase I (CPS I) is an enzyme located in the mitochondria, and it plays a crucial role in the urea cycle. The primary function of CPS I is to catalyze the conversion of ammonia and bicarbonate into carbamoyl phosphate, which is the first step in the urea cycle. This reaction is essential for detoxifying ammonia, a toxic byproduct of protein metabolism, into urea, which can then be excreted by the kidneys.

The urea cycle occurs in the mitochondria of liver cells, and CPS I is activated by N-acetylglutamate, which is synthesized in response to an increase in amino acids in the body. By facilitating the conversion of ammonia to carbamoyl phosphate, CPS I effectively helps to regulate nitrogen metabolism and prevents hyperammonemia, a condition that can result from excess ammonia in the bloodstream.

Other locations or roles mentioned in the alternatives do not accurately reflect the function or location of CPS I. The cytosol is where various metabolic reactions occur, including nucleotide synthesis, but CPS I is not involved in this pathway. The nucleus is responsible for protein synthesis but does not contain CPS I. The endoplasmic reticulum