Glycogen. At the core of the glycogen molecule is the protein glycogenin (yellow). Each line represents glucose molecules joined by an α-1,4-glycosidic linkage. The nonreducing ends of the glycogen molecule form the surface of the glycogen granule. Degradation takes place at this surface.

[Information from R. Melendez et al. Biophys. J. 77:1327–1332, 1999.]