Question

Most digestion and absorption of food takes place in

• A. Stomach
• B. Liver
• C. Large intestine
• D. Small intestine

Answer 1

The correct option is D

Small intestine

The correct option is option D.

Explanation for the correct option:

1. Most of the digestion and absorption takes place in the large intestine.
2. The liver secretes bile juice that emulsifies the fat and helps in its absorption.
3. The pancreas secretes many enzymes that activate other enzymes which help in the digestion of food:
4. Trypsinogen (inactive) is activated by enterokinase
5. Trypsin converts proteins into polypeptides and di-peptide.
6. Chymotrypsinogen is activated by enterokinase.
7. Carboxypeptidase converts polypeptide into amino acids.
8. Amylase converts starch into disaccharides.
9. Cholesterol esterase acts on lipids and breaks them into mono and triglycerides.
10. Some enzymes are also secreted by the wall of the intestine like Maltase, sucrase, lipase, lactase and phosphatase.
11. 90% of digested food is absorbed by the small intestine.
12. The wall of the small intestine gets modified and forms microvilli.
13. In these blood capillaries and lacteal ducts are found.
14. Blood capillaries absorb monosaccharides and amino acids. Lacteal ducts absorb lipids.
15. Water-soluble vitamins are absorbed in the blood directly ,and others are absorbed with the help of transporters.
16. Minerals are also absorbed with water.

Explanation for the incorrect options:

Option A: In the stomach, food is digested partially and not absorbed.

Option B: The liver secretes bile juice that enters the small intestine through a duct. Digestion and absorption do not take place in the liver.

Option C: Only 5% of water is absorbed in the large intestine. No digestion takes place.

Final answer: Most digestion and absorption of the food takes place in the small intestine.