Many polysaccharides play biologically significant rolls as structural components within the cells and tissues of many diverse types of organisms. Important polysaccharides include amylose, amylopectin, glycogen, cellulose and chitin.

The orientation of the glycosidic bond in starch and glycogen permits the polymer chains to twist into compact spirals while in cellulose, this twisting is not permitted. Cellulose chains are straight, the hydroxyl groups allowing for extensive cross-linking to occur.

Note: When plants come up in these discussions, it is almost always because the context gives us a useful field to discuss basic principles. A real key to understanding a concept is to see it play out in different contexts. In the above discussion, I want you to get ever more comfortable seeing terminology like 'glycosidic bond' in usage, or to be thinking about the role of hydroxyl groups in determining macromolecular superstructure.