Digestion in the Small Intestine

It is located between the stomach and the large intestine. It consists of the duodenum, jejunum and ileum.

The main function of small intestine is to absorb nutrients and minerals from food.

The pancreas which is located behind the stomach, produces a juice containing several enzymes that break down carbohydrates, fats and oil and proteins.

They are:

I.Pancreatic amylase; this breaks down starch and converts it to maltose.

II. Pancreatic lipase; this breaks fat and oil, it converts it to fatty acid and glycerol. In the duodenum, bile is also produced here from the liver. This bile aids the digestion of the lipids in the small intestine. The fat and oil are broken down into tiny droplets for easy digestion.

III. Protease; this is also called trypsin, this breaks down protein. Protein is also converted into peptides.

In the ileum

Fat and oil was broken down into its simplest form in the duodenum.

The substances left to be digested are maltose (starch) and peptides (protein).

In the ileum, there is a secretion from the glands lining the small intestine walls.

This is called the succus entericus. This contains digestive enzymes which completes the digestion process of starch and protein.

This succus entericus contains the following enzymes:

I. maltase; which breaks down maltose into glucose.

ii. protease; which breaks down peptides into amino acids.