Digestive Enzyme Function in the Process of Digestion

Digestion of food starts in the mouth and amylase is the first digestive enzyme acting on the food. From mouth to anus the digestive tract of human being produces

22 different enzymes

that act on the food for the process of digestion. This article gives a brief description of all the processes that enunciate the function of enzymes in digestion.



Mouth is the first place where the food is kept in. Salivary glands of the mouth secrets enzymes called salivary amylase that breaks the bigger molecules of starch to smaller sugars. Production of this enzyme is stimulated by the process of chewing. Thus it is important to chew throughly to get the proper proportion of amylase for the digestion.


Stomach is the place for digestion of proteins and ionization of minerals. Enzyme pepsin is secreted in the stomach for this purpose. Hydrochloric acid is secreted by the parietal cells of the stomach. Pepsin and hydrochloric acid act on protein to break down into amino acids.

Small intestine:

Small intestine is the place where several enzymes which are secreted by pancreas, liver and the gallbladder meet. It is the main place of digestion in our body. Some of the important actions of enzymes happen in small intestine. Here is the list of the actions of digestive enzymes in small intestine:

  • Salivary amylase breaks starch and glycerol into sugars
  • Pepsin, the main gastric enzyme, breaks proteins into smaller peptide fragments
  • Gastric lipase acts on tributyrin for digestion of fat
  • Gelatinase breaks type 1 and type 5 gelatin and type 4 and type 5 collagen
  • Gastric amylase breaks starch further
  • Pancreatic trypsin breaks proteins at the basic amino acids and chymotrypsin cleaves proteins at the aromatic amino acids.
  • Pancreatic steapsin converts triglycerides into glycerol and fatty acids.
  • Elastases break protein elastin and nucleases break nuclec acids such as DNAase and RNAase.
  • In small intestine sucrase cleaves sucrose into glucose and fructose and maltase converts maltose to glucose.
  • Similarly isomaltase converts maltose to glucose and lactase breaks lactose into glucose and galactose. Intestinal lipase cleaves down the fatty acids into smaller particles of fats.

All the above reactions happen in small intestine with aid of digestive enzymes.

Large Intestine:

Large intestine is also called as colon. It is basically the place of absorption of the water, electrolytes and vital products of digestion. It from large intestine the waste products are excreted out after the process of digestion.

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