Glycogen is digested back into glucose when energy is needed. The liver and skeletal muscle are major depots of glycogen. But for most of us, carbo loading leads to increased deposits of fat. Cellulose Cellulose is probably the single most abundant organic molecule in the biosphere. It is the major structural material of which plants are made.
Wood is largely cellulose while cotton and paper are almost pure cellulose.
Like starch, cellulose is a polysaccharide with glucose as its monomer. However, cellulose differs profoundly from starch in its properties. Because of the orientation of the bonds linking the glucose residues, the rings of glucose are arranged in a flip-flop manner. This produces a long, rigid molecule. There are no side chains in cellulose as there are in starch.