Final answer:
A polysaccharide is a large, complex carbohydrate composed of many monosaccharide monomers linked by glycosidic bonds, which forms structures such as starch, glycogen, cellulose, and chitin in living organisms.
Step-by-step explanation:
A polysaccharide is a complex carbohydrate polymer that is composed of long chains of monosaccharide monomers. These monomers are joined together by glycosidic bonds, resulting in a molecular structure that can be straight or branched, and vary widely in length, from ten to thousands of sugar units.
Common examples of polysaccharides include starch, which is a primary form of energy storage in plants, and glycogen, which serves a similar purpose in animals. Another important polysaccharide is cellulose, the structural component of the cell walls in plants, which provides rigidity and strength. Moreover, chitin is a polysaccharide found in the exoskeletons of insects and the cell walls of fungi, and it is distinguished by a modified form of glucose in its composition.
Unlike smaller carbohydrates such as mono- and disaccharides, polysaccharides are typically not sweet-tasting and have limited solubility in water. Their primary functions in living organisms are to store energy and to form the structures necessary for life, such as cell walls and exoskeletons.