Is synthesis of urea a function the liver?

Yes, the synthesis of urea is a function of the liver. Urea is the main nitrogenous waste product of protein metabolism in the body. It is synthesized in the liver as a result of the urea cycle, which involves the conversion of ammonia to urea.

The urea cycle takes place in the liver cells, specifically in the mitochondria. The cycle begins with the formation of carbamoyl phosphate from ammonia and bicarbonate. This reaction is catalyzed by the enzyme carbamoyl phosphate synthetase I (CPS I). Carbamoyl phosphate then reacts with ornithine to form citrulline, which is catalyzed by the enzyme ornithine transcarbamoylase (OTC).

Citrulline is transported out of the mitochondria into the cytoplasm, where it reacts with aspartate to form argininosuccinate. This reaction is catalyzed by the enzyme argininosuccinate synthetase (ASS). Argininosuccinate is then cleaved into arginine and fumarate by the enzyme argininosuccinate lyase (ASL).

Arginine is transported back into the mitochondria, where it reacts with water to form urea and ornithine. This reaction is catalyzed by the enzyme arginase. Ornithine is then recycled back into the urea cycle.

The urea cycle is a continuous process that results in the conversion of ammonia to urea. Urea is transported in the blood to the kidneys, where it is excreted in the urine.