Cellulose

Complex carbohydrate (polysaccharide) consisting of 1,000–3,000 or more glucose units in a linear chain structure that can pack into fibres of great tensile strength. The basic structural component of plant cell walls, cellulose is the most abundant of all naturally occurring organic compounds (90% of cotton and 50% of wood).

Mammals (including humans) cannot digest cellulose, but bacteria in the rumens of cattle and other ruminants and protozoans in the gut of termites produce enzymes that can break it down. Soil fungi can also break down cellulose. Its most important uses are in wood, paper, and fibre products, as an ethanol and methanol source, and specialized applications. Cellulose derivatives are used in plastics, photographic films, rayon fibres, cellophane, coatings, explosives (e.g., nitrocellulose), and foods (e.g., the stabilizer and thickener carboxymethylcellulose).