why is cell membrane called selectively permeable membrane
Answers
Answer:
The cell membrane is a very thin layer of protein and fat. It allows only selective substances to pass through it, hence,it is called a selectively permeable membrane
Selectively Permeable Membrane
The plasma membrane is called a selectively permeable membrane as it permits the movement of only certain molecules in and out of the cells. Not all molecules are free to diffuse. If plasma membrane ruptures or breaks down then molecules of some substances will freely move in and out of the cells. As the plasma membrane acts as a mechanical barrier, the exchange of material from its surroundings through osmosis or diffusion in a cell won’t take place. Consequently, the cell would die due to the disappearance of the protoplasmic material. It allows hydrophobic molecules and small polar molecules diffuse through the lipid layer, but does not allow ions and large polar molecules cannot diffuse through the membrane.
Proteins In Plasma Membrane
There are two types of proteins molecules are found in the plasma membrane:
(i) Intrinsic proteins -They completely cover the lipid bilayer.’
(ii) Extrinsic proteins – These occur either on the outer surface or on the inner surface of the lipid layer.
Functions Of Plasma Membrane
The plasma membrane forms a barrier between the cell organelles from the outside environment.
It allows only certain molecules to pass through it.
It facilitates communication and signalling between the cells.
Answer:
because cell membrane is allowed Material in or out from the cell
Explanation:
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