Cellulose is the main chemical that forms the main structure of plants.
Cellulose is made from a form of glucose and makes up most of the cell wall of plant cells. This is what keeps a plant in shape. Cellulose is not digestible by humans. It also is used in some wood and paper products. It is a polysaccharide, which is repeating units of a monosaccharide joined together by a glycosidic bond by a condensation reaction, there is a by-product of water, found in plants. It is very tough because when you join beta glucose together, they are opposite ways up, the bonds are straight, forming straight chains. There is hydrogen bonds between the polymers.