How do the structures of starch, glycogen, and cellulose affect their function?

Starch refers to a polysaccharide found in various parts of the plants. In starch, the unbranched chain is wound into a tight coil that makes the molecule very compact. The chains of alpha-glucose are associated with glycosidic bonds. It is the prime energy source in various diets.

The main function of starch is storing energy and due to its composition, it is well-suited for this function. Due to its compactness lots can be stored in a small space, it is insoluble so it does not diffuse out of the cells easily and does not influence osmosis. It gets hydrolyzed to alpha-glucose, which get transported easily and is used in respiration.

Glycogen is identical to starch, however, comprise shorter chains and are more highly branched. It is stored in small granules in the liver and muscles. Due to smaller chains, they are easily hydrolyzed to alpha-glucose. It is suitable for storing purposes due to similar reasons like starch.

Cellulose comprises beta glucose, not alpha. This small change has a big variation in the composition. In spite of coiling like starch, cellulose exhibit straight unbranched chains. These run parallel to each other, permitting hydrogen bond cross-linkages between the chains. The molecules of cellulose are aligned to produce microfibrils that are organized to produce fibers. The main function of cellulose is to provide rigidity to the cells and to inhibit bursting of the cells due to osmosis.