Membrane fluidity is affected by 1 temperature cholesterol t

Membrane fluidity is affected by?

1 temperature, cholesterol, types of fatty acids.

2 size of molecules, polarity of molecules, temperature.

3 types of fatty acids, waters affinity for hydrogen bonding.

4 hydrophilic tails, hydrophobic heads, cholesterol.

Solution

Que-1: Membrane fluidity is affected by?

Answer: 1 temperature, cholesterol, types of fatty acids

Reason:

Membranes are fluid structures, and the fluidity depends on fatty acid composition and cholesterol content. The fluidity of the fatty acids increases with the degree of unsaturation and decreases with the length of the linear hydrocarbon chain.

Lipid rafts are the intermittent molecules and formed of between sphigolipids with micelles and cholesterol along with proteins and enabling the lipid bilayer thicker and the membrane proteins tend to be accumulated. According to homeoviscous theory and adaptation, the more acyl chain addition (packaging) to the long chained fatty acids in the biological phospholipids membranes associated with decreased fluidity because of the more viscosity. Long unsaturated (presence of double and triple bonds between fatty acid carbons) fatty acids with trans- configuration possess more melting temperature associated with less membrane rigidity.

When a cell is under heat stress or heat shock and it can exert severe denaturation action on plasma membrane. Therefore, a higher content of unsaturation has leading to lower resistance to heat. Thereby it is crucial to increase higher saturated hydrocarbon level in fatty acids and it provides more membrane fluidity with increasing temperature lipid melting temperature. Therefore, embrane fluidity is affected by temperature & cholesterol. A high ratio of cholesterol of phospholipid level can exert resistance to the cells with increasing heat as increase in steroidal ring content with saturated hydrocarbon fatty acids.

In the presence of cholesterol, the fluidity of fatty acids decreases, though the temperature increases. Thus, cholesterol is essential for the maintenance of proper fluidity of the membrane structures.