What defines disaccharides and polysaccharides?

Disaccharides and polysaccharides are defined based on their structure and the number of sugar units they contain. Disaccharides consist of two monosaccharide units linked together through a glycosidic bond. This double-sugar configuration plays a crucial role in energy storage and metabolism. Common examples of disaccharides include sucrose (table sugar) and lactose (milk sugar).

Polysaccharides, on the other hand, are longer chains that consist of three or more monosaccharides. These complex carbohydrates serve multiple functions, including energy storage and structural purposes. Starch, glycogen, and cellulose are notable examples of polysaccharides, each fulfilling different roles in biological organisms.

This distinction between the two types of carbohydrates underlines the diversity and essential functions of carbohydrates in living systems. Each type is fundamentally important for various biological processes, which is accurately reflected in the correct choice, highlighting the nature of both disaccharides and polysaccharides.