University:
Liberty University
Course:
BIOM 500 | Introduction to Biomedical Sciences
Academic year:

2024
Views:

410

Pages:

5
Author:

Sheha A.

Digestion of Carbohydrates Absorption of monosaccharides does not require any digestion whereas absorption of disaccharides requires digestion of polysaccharides. Digestion of carbohydrates occurs briefly in mouth and largely in intestine. a) Digestion of Starch Digestion of starch begins in mouth and continues in intestine. Salivary amylase and pancreatic amylase are the important enzymes of starch and glycogen digestion. Cl- is an activator of these enzymes. I. Digestion in mouth: Salivary amylase of saliva starts the digestion of cooked starch in the mouth. Very little digestion takes place in the mouth as the food remains in the mouth for a very short period of time. Salivary amylase randomly hydrolyzes α-1,4 glycosidic bonds of starch and glycogen to give short oligosaccharides and maltose. II. Digestion in the Stomach: Salivary amylase action continues for some time at the center of the food bolus in the stomach. When the food bolus is mixed with gastric juice, the action of amylase stops due to acidity (pH of gastric content is less than 4 due to presence of HCl, which denatures and inactivates salivary amylase). III. Digestion in the Small Intestine: Pancreatic amylase continues the digestion of starch in the intestine. The action is similar to salivary amylase. The digestion of disaccharides and oligosaccharides is carried out by disaccharidases and oligosaccharidases which are present in the brush border of the small intestine. These enzymes are also referred to as brush border enzymes. Maltase digests maltose, maltotriose, limit dextrins and non-branched oligosaccharides. It removes single glucose residues from the non-reducing ends. Maltase enzyme does not act on branched points.