Just beneath the cell wall, there is a soft living membrane surrounding the whole protoplasm. This is called cytoplasmic membrane or cell membrane.
Stucture: Plasma membrane is bi-layered. Under electron microscope there revealed a light layer between two dark layers. In the cell membrane of some epithelial cell there found some finger-like out growth-these are called Microvilli (Singular: Microvillus). They increase the absorption surface of the cell. The membrane between two adjacent cells modified in various form to make the connection between two cells rigid. They also make the movement of different substances between the cells easier. In many cells spaces in the cell membrane may be broader.
Functions of Cell membrane:
(a) Transportation of different materials inside and outside the cell,
(b) Absorption of different substances (mainly nutrients) from outside the cell,
(c) protection of the cell body and giving the cell a definite shape.
