Jharkhand PSC Prelim Exam 2006 Solved Paper

(1) Renin and lactase are enzymes necessary to break down and digest milk. As with lactase, the concentration of the enzyme rennin that breaks down the casein also declines with age in all mammals.
Renin is an enzyme which has the function of digesting only milk proteins and Lactase - Digests lactose into glucose and galactose.
By the age of two, the rennin and lactase enzymes start to disappear in the human body.