Which polymer is formed when glucose units are joined?

When glucose units are joined together, they can form several different polymers, the primary ones being starch and cellulose. Both of these polysaccharides are composed of long chains of glucose monomers linked together in various ways.

Starch is a polysaccharide that serves as an energy storage molecule in plants. It is made up of two types of molecules: amylose, which is a long, unbranched chain of glucose molecules, and amylopectin, which is a branched chain. In starch, the glucose units are primarily linked by alpha glycosidic bonds, which allow for easier breakdown by enzymes.

Cellulose, on the other hand, is the main structural component of plant cell walls. This polymer is also made up of glucose units, but it is formed through beta glycosidic bonds, which create a straight, unbranched chain that allows for strong hydrogen bonding between chains, contributing to its rigidity and strength.

Given that both starch and cellulose are formed from glucose units, the statement that both can be formed when glucose is joined is accurate. Therefore, stating that the correct answer encompasses both starch and cellulose reflects an understanding that glucose can polymerize in different configurations to create distinct compounds with different functions.