(1) A polysaccharide consisting of a linear chain of β (1→4) linked D-glucose units: (C6H10O5) n.
(2) The fibrous carbohydrate found in the cell walls of green plants, some algae and oomycetes. It provides strength and rigidity to plant cells.
The cellulose is a straight chain polymer of carbohydrates. Unlike starch, it lacks coiling and it forms a rather rigid, rod-like conformation.
Humans cannot digest cellulose but a dietary fiber that serves as a hydrophilic bulking agent in feces. In some animals like ruminants cellulose is digestible because they have symbiotic microorganisms in their guts that help digest cellulose.
Word origin: French, from cellule (biological cell).
Related form: cellulosic (adjective)