How does rennin cause curdling of milk?
Rennin is produced in the form of inactive prorennin. After consumption of milk, the hydrochloric acid in the gastric juice present in the stomach activates prorennin and converts it into its active form, rennin. There is a caseinogen enzyme present in the milk, which has four types of molecules. Rennin precipitates three of them, namely alpha-s1 and alpha-s2 casein and beta casein, in the presence of calcium in the milk. The fourth molecule in the caseinogen enzyme, called kappa casein is not precipitated by calcium. Kappa casein is known to prevent the precipitation of alpha and beta caseins. Since coagulation is necessary, rennin enzymes inactivate kappa casein. In this way, milk is coagulated and properly digested, so that young mammals get all its advantages. The most optimum temperature required for the reaction of milk and rennin is 37 degree Celsius. At higher temperatures, the rennin enzyme molecules break down and the action of rennin on milk ceases. If the temperature falls,
