LIFE SCIENCE

Detailed explanation-1: -There are three major classes of membrane lipid molecules-phospholipids, cholesterol, and glycolipids.

Detailed explanation-2: -With few exceptions, cellular membranes-including plasma membranes and internal membranes-are made of glycerophospholipids, molecules composed of glycerol, a phosphate group, and two fatty acid chains. Glycerol is a three-carbon molecule that functions as the backbone of these membrane lipids.

Detailed explanation-3: -In addition to the phospholipids, the plasma membranes of animal cells contain glycolipids and cholesterol. The glycolipids are found exclusively in the outer leaflet of the plasma membrane, with their carbohydrate portions exposed on the cell surface.

Detailed explanation-4: -The plasma membrane is made up primarily of a bilayer of phospholipids with embedded proteins, carbohydrates, glycolipids, and glycoproteins, and, in animal cells, cholesterol.