EVERYDAY SCIENCE

Detailed explanation-1: -Most plasma membranes consist of approximately 50% lipid and 50% protein by weight, with the carbohydrate portions of glycolipids and glycoproteins constituting 5 to 10% of the membrane mass.

Detailed explanation-2: -The principal components of the plasma membrane are lipids (phospholipids and cholesterol), proteins, and carbohydrate groups that are attached to some of the lipids and proteins. A phospholipid is a lipid made of glycerol, two fatty acid tails, and a phosphate-linked head group.

Detailed explanation-3: -Lipid-that is, fatty-molecules constitute about 50% of the mass of most animal cell membranes, nearly all of the remainder being protein. There are approximately 5 × 106 lipid molecules in a 1 m × 1 m area of lipid bilayer, or about 109 lipid molecules in the plasma membrane of a small animal cell.

Detailed explanation-4: -The organelle called ‘endoplasmic reticulum’ occurs in both plants and animals and is a very important manufacturing site for lipids (fats) and many proteins.