Explain the structure of plasma membrane. What are its major functions?

Structure of plasma membrane:
*According to the fluid mosaic model the plasma membrane is made up of phospholipid bilayer with various protein floating in it.
*Two different types of proteins have been identified in the plasma membrane based on their location and association i.e., peripheral and integral membrane proteins.
*Each phospholipid is composed of a hydrophilic head and a hydrophobic tail.
*The hydrophilic heads are attracted to the water in the cytoplasm of the cell, as well as to the water in the surroundings of the cell.
*The hydrophobic tails are repelled by water and are attracted to each other.
*It is because of this attraction and repulsion that the bilayer is a stable structure despite its fluidity.

Functions of Plasma membrane:-
*Plasma membrane gives shape to the cell.
*It separates the content of cells from their external environment acting as a mechanical barrier and protect the cell from external injury.
*Regulates the movement of various material into and out of the cell.
*It maintains a constant environment inside the cell known as homeostasis.