1. Protein digestion
(i) Inactive trypsinogen is converted to active trypsin under the action of enterokinase enzyme. Trypsin converts peptone into dipeptides and polypeptides.
(ii) Inactive chymotrypsinogen is converted to active chymotrypsin with the help of trypsin enzyme. Chymotrypsin breaks down milk casein into paracasein.
(iii) Elastase enzyme breaks down elastin into peptides.
(R) Peptides are produced from collagen by the action of collagenase enzyme.
2. Carbohydrate digestion
(i) Enzyme amylase breaks down starch and glycogen into maltose, maltotriose and dextin.
(ii) Maltose is converted to glucose in the presence of maltase enzyme.
3. Lipid digestion
(i) The enzyme lipase breaks down lipids into fatty acids and glycerol.
(ii) Phospholipids are converted into fatty acids and monoglycerides in the presence of phospholipase enzymes.