Carbohydrates are among the essential nutrients in the balanced human diet. Two kinds of carbohydrates can be digested by the human digestive system– sugar and starch.
Sugar is broken down in the GI tract (specifically in the small intestine). It is brought about by three enzymes present in the mouth, viz, Lactase, Sucrase and Maltase.
Lactase: Breakdown of Lactose to glucose and galactose
Sucrase: Breakdown of Sucrose to glucose and fructose
Maltase: Breakdown of Maltose to two units of glucose
Similarly, starch is broken down with the aid of the Amylase enzymes, which are present in the mouth and the stomach. After the process of digestion, carbohydrates are absorbed in the small intestine.
The monosaccharides are ultimately absorbed into the bloodstream and transported to the liver. Some indigestible carbohydrates are digested by micro-organisms (bacteria) in the large intestine.