Glycogen is a condensation polymer of `alpha - D` glucose. Starch is not a single compound but is a mixture of two components -a water soluble component called amyldse (15 - 20%) and water insoluble component amylopection (80 - 85%). Amylose is a linear polymer of `alpha- D` glucose. But both glycogen and amylopectin are branched polymers of `alpha - D -` glucose, father glycogen is more highly branched than amylopectin as amylpectin chain consists of `20 -25` glucose units, glycogen chains consist of `10 - 14` glucose units.
