Cellulose is a complex carbohydrate that is composed of glucose units,forms the main constituent of the cell wall in most of the plants,and is important in the manufacture of numerous products,such as paper,textiles and explosives etc.mammals (including humans)cannot digest cellulose,but bacteria in rumen of cattle and other ruminants produce enzymes that can break down the cellulose.cellulose are used to ake wood,paper,and fibre etc
The human digestive system has lots of enzymes, and acids to break down and assimilate all kinds of different foods, but we do not have the enzymes needed to break down cellulose. Cows, Goats, Sheep and other animals that graze on many organic foods do have the enzymes needed to break down cellulose.