Question

Digestion of protein is completed in
(a)Stomach
(b)Duodenum
(c)Ileum
(d)Duodenum and ileum

Answer 1

Hint: Digestion breaks the proteins down to be used within the metabolism. Protein is an important nutrient needed by the physical body for growth and maintenance.

Complete answer:
Protein breakdown begins within the stomach. An enzyme within the juice of the stomach starts the digestion of swallowed protein. Protein digestion within the stomach occurs mainly by the action of hydrochloric acid (HCl) and an enzyme called pepsin. The chyme first enters the duodenum, which is a part of the small intestine.
Further digestion of the protein is completed within the small intestine. Here in Duodenum several enzymes from the digestive juice and therefore the lining of the intestine perform the breakdown of giant protein molecules into small molecules called amino acids. In the ileum, these small molecules are often absorbed from the hollow of the small intestine into the blood then carried to all or any parts of the body.

Additional information :
Details on protein digestion -
-The stomach releases gastric juices containing hydrochloric acid and therefore the enzyme, pepsin, which initiates the breakdown of the protein.
-Pepsin, line the stomach, dismantles the protein chains into smaller and smaller fragments.
-The stomach empties the chyme containing the small protein into the tiny intestine, where the bulk of protein digestion occurs.
-The pancreas secretes digestive fluid that contains more enzymes that further break down the protein fragments. The 2 major pancreatic enzymes that digest proteins are chymotrypsin and trypsin.
-The goal of the digestive process is to interrupt the protein into dipeptides and amino acids for absorption.
-In the lower parts of the small intestine, which is in the ileum, the amino acids are transported from the intestinal lumen through the intestinal cells to the blood.

So, the right answer is ‘Duodenum and ileum’.

Note: -Most of the digestive enzymes are secreted in their inactive precursors known as zymogens.
-Trypsin, which is secreted as trypsinogen, gets activated by enterokinase in the duodenum.