Describe the fluid mosaic model of plasma membrane.

Dear Student

The structure of plasma membrane was proposed by Singer and Nicolson in 1972. It is widely accepted as fluid mosaic model. According to this model-

• Cell membrane is composed of a lipid bilayer, with a polar head towards the outer side, and hydrophobic tails towards the inner side. So, the non-polar,  hydrophobic tail is protected from aqueous environment.
• Proteins and carbohydrates are also present in the membrane.
• Membrane proteins can be integral (lying buried in the membrane) or peripheral (lying on the surface of the membrane).
• Fluid mosaic model  shows  the quasi-fluid nature of lipids enables lateral movement of proteins within the bilayer.
• Fluidity is the measure of the ability of the membrane to allow movement within itself.
• Fluid nature of the membrane is important for cell division, cell growth, the formation of intercellular junctions, secretion and endocytosis.