Glycogen is a polysaccharide made up of almost 2000−200000 units of α− D glucose, it is a branched structure, there are two types of bonds present in glycogen as the α1−4 glycosidic and α 1- 6 glycosidic bond.
Glycogen stores in cells of liver and muscles and gives the red color with iodine also it is named as animal starch.