- The process by which end products of digestion enters into the blood is called Absorption.
- The main site of absorption is small intestine.
Mechanism of Absorption
a. Active transport
- Movement of nutrients across cell membrane from the area of low concentration to higher concentration with the cost of energy.
b. Passive transport
- Movement of nutrients from area of higher concentration to lower concentration. It does not use energy.
c. Faciliated diffusion
- Movement of nutrients from area of higher concentration to lower using carrier protein.
d. Endocytosis: Mechanism of absorption in which cell membrane engulfs material.
Absorption of carbohydrate:
Simple sugars are absorbed from small intestine to portal blood system then into lives in the form of glucose.
Absorption of Protein:
Absorption way is similar to carbohydrate but this is absorbed in the form of Amino acids.
Absorption of Fat
These are absorbed in the form of fatty acids and monoglycerides. Some di and tri glycerides can be absorbed. They are absorbed through intestinal membrane.
Absorption of water
Water is absorbed in small intestine through osmosis and enters blood stream