What is Cellulose?
Cellulose is a biopolymer made from repeating monomer units of $\beta$-glucose. Shown to the right is the three dimensional structure of an $\alpha$-glucose and $\beta$-glucose monomer.
Often cellulose is used in plants in order to provide strength in plant walls. Cellulose is present in most plant matter and can be appropriated in chairs, wooden furniture and other such wooden construction (cellulose comprises of about 40-50% of wood). An important use of cellulose is the production of glucose monomer units in what's called cellulolysis which is a hydrolysis process. These glucose monomer units may be fermented at a later stage to produce ethanol which is an industrially important petrochemical.
Inter and Intra-molecular Structure and Properties
Cellulose is a very strong polymer, shown right is a structural diagram of cellulose.
Cellulose is a condensation polymer and is made via a process called a condensation polymerisation or a series of condensation reactions. A condensation reaction involves the reaction between two or more monomers with the elimination of a small molecule which is in this case, but not always, water. Due to cellulose's structure this polymer is particularly hard and strong, due to the molecule size cellulose is insoluble in water even though glucose monomers are. The formation of the glycosidic bonds between each monomer in alternating angles increases the stress limits of cellulose cue to compression and contraction. In addition to this the strong intra-molecular forces between the hydrogen bonding of the external hydroxy groups make cellulose particularly brittle and resistant to elastic forces. Hence due to these factors cellulose is an extremely strong biopolymer.