Final answer:
Starch, glycogen, and cellulose are important polysaccharides that serve different purposes in organisms.
Step-by-step explanation:
Starch, glycogen, and cellulose are all important polysaccharides that are composed of glucose units. Cellulose is a linear chain of glucose molecules and is a structural component of cell walls in plants and other organisms. Glycogen is a branched polymer and serves as the primary energy-storage molecule in animals and bacteria.
Starch is also a branched polymer and is the primary energy-storage molecule in plants. These molecules are important to certain types of organisms because they provide structural support, store energy, and serve as a source of nutrients.