The enzyme that acts on milk in the stomach is

The enzyme that acts on milk in the stomach is renin. Renin is produced by special cells in the stomach called chief cells. It is an enzyme that coagulates milk proteins in the stomach, making them easier to digest. This coagulation process is important for young mammals that rely on milk for their nutrition. Renin helps to slow down the passage of milk through the stomach, giving it more time to be broken down by other digestive enzymes. It is particularly important for the digestion of milk in infants, but its production decreases as we grow older and start consuming more solid foods.