Starch is not a single compound. It consists of amylose (15-20%) and amylopectin (80-85%). In contrast cellulose is a single compound. Amylose is a linear polymer of α-D- glucose while cellulose is a Condensation polymer of β-D-glucose. In amylose, C -1 of one glucose unit is joined to C – 4 of the other unit through glycosidic linkage. In cellulose, C -1 of one glucose unit is joined to C – 4 of the other emit through β- glycosidic linkage. Amylopectin has highly branched structure.
