Introduction:

Milk is an essential component of our diet, and it contains various nutrients that are necessary for our body. However, the digestion of milk in adults is different from that in infants. In adults, the initial step in the digestion of milk is carried out by a specific enzyme. Let us discuss this in detail.

Answer:

The initial step in the digestion of milk in adults is carried out by the enzyme rennin. Rennin is a proteolytic enzyme that is produced by the stomach and is also known as chymosin. The primary function of rennin is to curdle milk, which helps in the digestion of milk proteins.

Role of Rennin in Milk Digestion:

Rennin plays a crucial role in the digestion of milk in adults. The following points explain how rennin works in the digestion of milk:

- When rennin is released into the stomach, it acts on the milk protein called caseinogen.
- Rennin cleaves the peptide bond between the amino acids phenylalanine and methionine in caseinogen and converts it into casein, which is insoluble.
- The insoluble casein forms a clot in the stomach, which slows down the digestion process.
- The clot protects the milk proteins from being broken down too quickly and allows enough time for the stomach acid and other digestive enzymes to act on them.

Conclusion:

In conclusion, the initial step in the digestion of milk in adults is carried out by the enzyme rennin. Rennin curdles the milk protein, caseinogen, and converts it into an insoluble form called casein. This process helps in the digestion of milk proteins and protects them from being broken down too quickly.