Cellulose and starch have different three-dimensional shapes and properties as a result of differences in glycosidic linkages. Cellulose reinforces plant cell walls. Glycerol, a three-carbon alcohol 2. Nonpolar C-H bonds make the chain hydrophobic and not water soluble. Each of glycerol's three hydroxyl groups can bond to a fatty acid producing a fat.
Fats are insoluble in water.
The long fatty acid chains are hydrophobic because of the many nonpolar C-H bonds. One gram of fat stores twice as much energy as a gram of polysaccharide. More compact fuel reservoir than carbohydrate. Animals store more energy with less weight than plants which use starch, a bulky form of energy storage. Are major constituents of cell membranes.