What is Diffusion?

The movement of a substance from an area of high concentration to an area of low concentration is called Diffusion.

The cell membrane is selectively permeable in nature. It only allows specific materials to enter and leave the cell.

It is made up of

cell membrane

Gases and water freely move in and out of the cell.

For example,

Carbon dioxide molecules can freely diffuse in and out of the cells as follows:

When cells undergo cellular respiration, a lot of carbon dioxide accumulates in the cells, and there is very little carbon dioxide present outside the
Thus, carbon dioxide molecules move outside the
Now, there is very little oxygen left in the cells, after
So, the oxygen from outside the cells moves in through the plasma
Thus, both the gases move from their area of higher concentration to an area of lower concentration. This process is called Diffusion which does not require

Thus, diffusion is a process in which transportation of several substances is carried out across the cell membrane without expenditure of energy.

Diffusion

Diffusion	The movement of a substance from an area of high concentration to an area of low concentration is called Diffusion. No energy is required.