Starch: Starch is the main storage carbohydrate source in plants.
Starch serves as a carbohydrate energy store
Cellulose: Cellulose is the main structural component of the cell wall of plants.
Cellulose is involved in the building of cellular structures like cell walls.
Glycogen: Glycogen is the main storage carbohydrate energy source of fungi and animals.
Glycogen serves as a carbohydrate energy store.
Starch, cellulose, and glycogen are polysaccharides found in organisms. Starch is found in plants as their major storage form of carbohydrates. Linear chains of starch are called amylose and when branched they are called amylopectin. Glycogen is similar to amylopectin but is highly branched. It is the major carbohydrate storage form in animals and fungi. Cellulose is a linear polysaccharide, which forms hydrogen bonds among several cellulose chains to form a fibrous structure. It is the major component of the cell wall of plants, some algae, and fungi. Thus, the main difference between starch cellulose and glycogen is their role in each organism.