How is the fluidity of a biological membrane maintained What

How is the fluidity of a biological membrane maintained? What is the function of cholesterol in the membrane?

Solution

The biological membrane not only separates cell from the rest of the world but also functions as selectively permeable membrane to communicate and interchange matter with outer membrane. For which it needs to be semifluid in nature and allowing proteins to rotate, maintain its integrity in change of temperature (high and low temperatures). The lipid bilayer thus have about 50% of cholesterol to zig zag through the lipid bilayer buffering the liquidity of the membrane in a state of equilibrium to facilitate functioning of the cell or organelle. The membrane phospholipid, protein composition, and lipids with single and double bond (saturated and unsaturated lipids) also determine membrane fluidity. Cholesterol plays the major role in maintaining fluidity of the membrane by preventing crystallization of phospholipids by separating them.