Elasticity of Cell Membrane

A cell membrane defines a boundary between the living cell and its environment. It consists of lipids, proteins,carbohydrates etc. Lipids and proteins are dominant components of membranes. One of the principal types of lipids in membranes is phospholipid. A phospholipid molecule has a polar hydrophilic head group and two hydrophobic hydrocarbon tails. When a quantity of lipid molecules disperse in water, they will assemble themselves into a bilayer in which the hydrophilic heads shield the hydrophobic tails from the water surroundings because of the hydrophobic forces.
The most widely accepted model for cell membranes is the fluid mosaic model proposed by Singer and Nicolson in 1972 [Science 175 (1972) 720]. In this model, the cell membrane is considered as a lipid bilayer where the lipid molecules can move freely in the membrane surface like fluid, while the proteins are embedded in the lipid bilayer. Some proteins are called integral membrane proteins because they traverse entirely in the lipid bilayer and play the role of information and matter communications between the interior of the cell and its outer environment. The others are called peripheral membrane proteins because they are partially embedded in the bilayer and accomplish the other biological functions. Beneath the lipid membrane, the membrane skeleton, a network of proteins, links with the proteins in the lipid membrane. A more recent model of the cell membrane as a self-organising, dynamic structure in which phospholipids flow in geometric patterns identical to those associated with 'Benard' convection' imbue the cell with it's elastic properties is gaining wide acceptance.