Starch consists of two components – amylase and amylopectin. Amylose is a long linear chain of α–D-(+)-glucose units joined by C₁-C₄glycosidic linkage (α -link).

Amylopectin is a branched-chain polymer of –D-glucose units, in which the chain is formed by C1-C4 glycosidic linkage and the branching occurs by C₁-C₆ glycosidic linkage.

On the other hand, cellulose is the main structural material of tree and other plants. Wood is 50% cellulose, while cotton wool is almost pure cellulose. It is linear chain natural polymers of β-D-glucose units joined by 1, 4-glycosidic linkage (natural linear polymers).