Question

what is the function plasma membrane​

Answer 1

$\purple{Functions\: of \:Plasma \:Membrane :}$

$\pink{A\: physical \:barrier :}$

• The plasma membrane surrounds all the cells.
• It even physically separates the cytoplasm which is the material which makes up the cell from the extracellular fluid outside the cell.
• This protects all the organelles of the cell from the outside environment and allows it to separate activities which occur inside and outside the cell.

$\pink{Selective\: Permeability :}$

• They are selectively permeable or semi-permeable which means that only certain molecules can pass through them.
• Water, oxygen, and carbon dioxide can easily travel through the membrane.
• Generally, ions like sodium, potassium and polar molecules can't pass through the membrane.
• They must go through specific pores in the membrane instead of freely diffusing through them.
• This way, the membrane can control the rate at which certain molecules can enter and exit the cell.

$\pink{Endocytosis \:and\: Exocytosis:}$

• Endocytosis happens when a cell ingests relatively larger contents than the single ions or molecules that pass through pores.
• Through endocytosis, a cell can take in large quantities of molecules or even whole bacteria from the extracellular fluid.

• Exocytosis happens when the cell releases these materials.
• The cell membrane plays an important role in both of these processes.
• The shape of the membrane itself changes to allow molecules to enter or exit the cell.
• It also forms vacuoles, small bubbles of membrane that can transport many molecules at one time in order to transport materials to different organelles in the cell.

$\pink{Cell \:Signaling:}$

• It is an another important function of the membrane which facilitates communication and signaling between the cells.
• It occurs through the use of various proteins and carbohydrates in the membrane.
• Proteins on the cell points out that cell so that other cells can identify it.
• The membrane also has receptors which allows it to carry out certain specific tasks when molecules like hormones bind to those receptors.

Answer 2

Answer:

Plasma membrane imparts shape to the cell.

Plasma membrane protects the cell from injury.

Plasma membrane regulates the cellular semi-permeability, reabsorption, excretion and secretion.

Various cell organelles can be formed within the cell, with the help of plasma membrane.

It regulates cellular interactions in the formation of tissues and the defence against foreign bodies.

The plasmalemma protects a cell from its surrounding environment.

Many membrane proteins serve as enzymes.

The cell membrane separates protoplasm from the external environment to maintain the individuality of the cell.

It also acts as a selectively permeable membrane to allow only specific substances in and out of the cell.