A polysaccharide is any of a group of polymers made from simple sugar molecules, or monosaccharides, linked by glycosidic bonds. Polysaccharides are insoluble and may serve as a store of energy, as in the case of starch and glycogen, or as a structural component, as in the case of cellulose which is found in the cell walls of plants. A single cellulose chain may contain as many as 10,000 units of glucose. Polysaccharides are part of the larger family of carbohydrates.