Discuss in detail the structure of plasma membrane with diagram.

Explanation

The detailed structure of the plasma membrane was studied only after the advent of electron microscope.
First of all study of plasma membrane of human RBC
The cell membrane of plasma membrane is composed of lipids that lipids are arranged within the membrane with the polar head towards the outer sides and the hydrophobic tails towards the inner part.
This ensures that the nonpolar tail of saturated hydrocarbons is protected from the aqueous environment. The lipid component of the membrane mainly consists of phosphoglycerides.

Biochemical investigation clearly revealed that the cell membranes also possess protein and carbohydrate. The ratio of protein and lipid varies considerably in different cell types.
In human beings, the membrane of the erythrocyte has approximately 52 per cent protein and 40 per cent lipids.
Depending on the ease of extraction, membrane proteins can be classified as integral or peripheral. Peripheral proteins lie on the surface of membrane while the integral proteins are partially or totally buried in the membrane.
An improved model of the structure of cell membrane was proposed by Singer and Nicolson (1972) widely accepted as fluid mosaic model figure. According to this, the quasi-fluid nature of lipid enables lateral movement of proteins within the overall bilayer. This ability to move within the membrane is measured as its fluidity.