It is composed of repeating units of glucose joined by β(1 → 4) linkages (see Figure 2.15) Cellulose is insoluble in water, dilute acids, alkalis, and organic solvents.

Cellulose is not easily digested by human system due to the lack of enzyme cellulose, which attacks the linkages in cellulose. Cellulose is as an important part of human diet as it acts as roughage.

Figure 2.15 Structure of Cellulose