Question

4 10 pts

Where do the different phases of digestion begin? Discuss each of the four major macromolecules are digested in our body? Tell where each begins digestion, ends digestion, and is absorbed.

Answer 1

Different phases of digestions - Cephalic phase , Gastric phase and Intestinal phase

Cephalic phase begins in stomach by secreting about 20% of gastric juice even when the food is being eaten and has not reached to stomach yet.

Gastric phase begins in stomach by secreting more than 2/3 gastric juice.

Intestinal phase begins in duodenum.

The 4 major macromolecules are -

Protein - Digestion begins in stomach and ends in intestine and is absorbed in small intestine .

Lipid - Digestion begins in stomach by very littile digestion and ends in small intestine and are absorbed in small intestine.

Carbohydrate - Digestion begins in buccal cavity and ends in small intestine.Absorption takes place in small intestine.

Nucleic acids - Digestion begins in small intestine , ends in it and is absorped here.