Question

Where do these processes specifically occur?

chemical digestion

lipid digestion

absorption of amino acid

absorption of dipeptides and tripeptides

Fat digestion

My resource is only telling me small intestine but I want to know specific names like duodenum, jejunum, ileum, ascending colon, etc.

Explanations would be helpful.

Answer 1

1. Chemical digestion occurs in duodenum by chemicals secreted by liver, pancreas and small intestine.

2. Bulk of Lipid digestion occurs in small intestine due to pancreatic lipase. It begins in stomach with the aid of lingual lipase and gastric lipase.

3. Absorption of aminoacids occurs in Jejunum, little in Ileum. Aminoacids are absorbed by a co transport mechanism with sodium ions.

4. Absorption of dipeptides and tripeptides in small intestine. These are absorbed into the small intestinal epithelial cell by cotransport with H+ ions via a transporter called PepT1.

5. Fat digestion mainly in intestine. Presence of fat in small intestine produces hormones that stimulate the release of pancreatic lipase from pancreas and bile from the liver, helping in emulsification of fats for absorption of fatty acids.