Question

Why cell membrane is called semi-permeable membrane?

Answer 1

Heya friend,

We have an outermost covering on cells which separates the contents of cell from its surrounding.


The plasma membrane is the outermost covering and it only allows some materials to enter and exit and thus it's called semi-permeable membrane.It is also known as cell membrane.

Plasma membrane is made of lipids and proteins and the substances like CO2, H20 and O2 moves in and out the cell through the process of diffusion.

Suppose if the concentration of CO2 or O2 is higher outside the cell so they will move in the cell.ie- from high concentration to lower concentration. Diffusion is the process of exchange of gases.

On the other side water (H2O) will move in and outside the cell by the process of osmosis. Osmosis is a process by which the water molecules enter and exit from cell through such semi-permeable membranes.

That's all!!

Hope it helps...!!!!!

Answer 2

see the attachment for answer