how milk & sugar is digested in alimentary canal ?

Milk digestion: The chief protein of milk caseinogens. An enzyme rennin curdles milk and caseinogens is converted to solid caseinogens is converted to solid casein. The Ca⁺⁺ present in the milk combines with casein to change it into calcium caseinate.

 Proennin + HCl → Rennin

Caseinogen -- Rennin – Casein

Casein + Rennin / HCI → Paracasein

Paracasein + Ca++ → Calcium paracaseinate.

Calcium paracaseinate + Pepsine →Protoeoses and peptones.

In the duodenum, the semi digested proteins become alkaline to be completely digested into amino acids. Protoeses, peptones and polypeptides are further broken by the enzyme trypsin and chymotrypsin coming from the pancreas. These enzymes are active in the alkaline medium which is maintained by the bile.

Enzyme enterokinase, peptidases etc. present in the succus entericus and the process of intestinal digestion takes place where these enzymes convert peptides into amino acid.

Sugar digestion: No digestions in stomach but a bit of it take place in mouth by the action of salivary amylase. Once food reaches the small intestine, pancreatic and intestinal juice enzymes digest starches and sugars. A pancreatic enzyme (amylase) starts the process by changing starches into a sugar called maltose. Three intestinal enzymes—maltase, sucrase, and lactase—digest sugars by changing them into simple sugars, namely glucose. Maltase digests maltose (malt sugar), sucrase digests sucrose (cane sugar), and lactase digests lactose (milk sugar). The end products of carbohydrate digestion are simple sugars.