What distinguishes the roles of different polysaccharides made from the same monomer?

The distinction among different polysaccharides made from the same monomer largely arises from variations in their structure and the way the monomer units are linked together. This structural difference affects several properties of the polysaccharides, including their function, solubility, and biological roles.

For instance, while glucose is the monomer for both starch and cellulose, starch is composed of branched chains of glucose units, leading to a structure that is more soluble and serves as an energy storage molecule in plants. In contrast, cellulose is composed of straight, unbranched chains of glucose that form strong fibrils, providing structural support in plant cell walls. These differences in linkage (such as the type of glycosidic bonds formed) and overall architecture of the molecules account for their distinct characteristics and functions despite having the same monomer. Thus, understanding the specific structural arrangements allows for a better grasp of how these polysaccharides fulfill various roles in biological systems.