Question

What mechanisms are involved in the absorption of digested food and water?

Answer 1

Hint: The process of absorption is done in the small intestine of the digestive system. Here the digested food is transported from the small intestine to the bloodstream through the membrane of the small intestine and via the bloodstream, it is transported to the entire body.

Correct answer:
Absorption is a process through which water and digested food are absorbed by the blood and supplied to all parts of the body.
The mechanisms involved in the process of absorption of digested food are simple diffusion, active transport, facilitated transport, and passive transport. For the absorption of water, the mechanism involved is osmosis.
1. Simple diffusion: This is the process in which the digested food molecules from the small intestine move from their region of higher concentration to their region of lower concentration that is the blood. This movement continues till they are uniformly distributed throughout the available space.
For example glucose, amino acids diffuse into the blood.
2. Active Transport: It is a process in which the digested food or solute moves from lower concentration to higher concentration with the help of external energy. For example, through the process of active transport, sodium ions are absorbed.
Facilitated transport: In this mechanism of transport the movement of the solute through a membrane occurs with the help of carrier proteins. For example, the absorption of digested proteins in the form of amino acids.
3. Passive transport: It is the process that involves the movement of the solute or digested food in simpler form through the cell membrane without the help of any external energy.
4. Osmosis: In the mechanism of osmosis the water moves from the region of high water concentration that is in the small intestine to the region of low water concentration that is in the blood through a semipermeable membrane.

Note:
The food we eat consists of various nutrients such as carbohydrates, proteins, fats, vitamins, minerals, and water.
After digestion, all these nutrients are broken down into their simpler form such as glucose, amino acids, fatty acids, glycerol, etc to get easily absorbed by the cells.
The mechanisms involved in the process of absorption of digested food are simple diffusion, facilitated transport, active, and passive transport.
The absorption of water involves the mechanism of osmosis.