Also known as rennin. It is an enzyme used to make cheeses (from milk). Chymosin occurs naturally in the stomachs of calves, and is one of the oldest commercially used enzymes. Chymosin (rennin) is chemically similar to renin, an enzyme that plays an important role in regulating blood pressure in humans.
An enzyme that curdles milk; present in the gastric juice of young ruminants. It is the preferred term for rennin because of possible confusion with the term renin.