Polysaccharides have diverse roles; which statement describes their functional range?

• A. They may have catalytic roles
• B. They are always energy sources
• C. They are always linear
• D. Some are for storage, others for structure

Answer: (D)

Polysaccharides show functional diversity because their specific sugar units, the type of glycosidic bonds, and their branching patterns create materials suited for different roles. Some are built to store energy and can be rapidly mobilized when needed—starch in plants and glycogen in animals. Others provide structure, forming rigid, supportive networks such as cellulose in plant cell walls and chitin in fungal cell walls and arthropod exoskeletons. Catalysis is typically performed by enzymes, not by the polysaccharide itself, and polysaccharides can be either branched or linear depending on their purpose. This combination of storage and structural functions best captures the functional range of polysaccharides.