Well, a polysaccharide is basically a very large carbohydrate that consists of many, many individual monosaccharides which are connected by Oglycoacetic bonds and the ore. Organisms in nature, including our own cells, use polysaccharides for one of two purposes. They either use polysaccharides as a form of storing energy. So we basically store glucose, as we'll see in just a moment, in the form we call glycogen, which is a polysaccharide. And whenever we want to form ATP molecules, we can break down glycogen into the individual glucose constituents and then we can feed those glucose molecules into the metabolism cycle glycolysis to basically form ATP molecules. Now, certain organisms, such as plants, as we'll see in just a moment, also use polysaccharides to basically form structure, give the cell structure and protection. Now, those polysaccharides that consist entirely of the same identical type of monosaccharide, these polysaccharides are known as homopolymers.