Figure 11 Glycogen, a starch . Glycogen storage granules can be seen in the cytoplasm of many types of cells, such as liver cells, muscle cells, and certain types of white blood cells. The electron micrograph shows a neutrophil, a type of white blood cell that is abundant in the body and that phagocytizes foreign material. The chief component of plant cell walls is a polysaccharide called cellulose. For this reason, cellulose works well as a biological structural material and occurs widely in this role in plants.
Chitin is a tough, resistant surface material that is also relatively indigestible.
Figure 12 Stucture of cellulose . Microfibrils, in turn, are composed of bundles of cellulose chains.