Give the biochemical composition of plasma membrane. How are lipid molecules arranged in the membrane?
Ans. The chemical composition of the plasma membrane can be summed up as 20-79% lipids, 20-70% proteins, 1-5% carbohydrates and 20% water.
Lipids are one of the major components that form the plasma membrane. The lipid molecules contain polar hydrophilic (water-loving), and non-polar hydrophobic (water-resisting) ends. The hydrophilic part forms the head of the molecule and the hydrophobic part forms two tails of the molecule.
The tails are found near the centre of the membrane.