Which of the following does not refer to the principal forms of carbohydrate present in our food ?

Cellulsoe act as protection to cell wall. This outer covering is positioned next to the cell membrane in most plant cells, fungi, bacteria, algae. The cell wall is composed of a network of cellulose microfibrils and cross-linked matrix of pectin polysaccharides. Though Cellulose is made up of glucose units, its complex structure do not allow it to be used as food.