Cellulose repeating monomeric units

Cellulose is a homopolymer of D-anhydroglucopyranose monomeric units connected through P-(l - 4 )-glycosidic linkages (Fig. 1). As illustrated, every other monomeric unit is rotated by approximately 180° about the long axis of the cellulose chain compared with its two neighboring monomeric units. Because of this, cellobiose is, in the strictest sense, properly considered the repeat unit... 

When monomeric units in a molecular chain (e.g., the glucose residues in cellulose) are regularly repeated, i.e., in crystals, they form shapes that can be described mathematically as helices. Helices of cellulose in crystals are described... 

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