Cellulose has what type of linkage?

• A. Alpha 1,4
• B. Beta 1,6
• C. Alpha 1,6
• D. Beta 1,4

Answer: (D)

Cellulose is built from glucose units connected by beta-1,4 glycosidic bonds. This beta linkage fixes the glucose units in a straight, extended chain, which allows many chains to align and form strong, hydrogen-bonded microfibrils that give cellulose its rigid, structural character. The straight, unbranched nature of the beta-1,4 linkage contrasts with alpha linkages found in starch and glycogen, which produce more coiled or branched structures that are more easily digested. A beta-1,6 linkage would imply a branching pattern not characteristic of the cellulose backbone, reinforcing why the connecting point of cellulose is specifically beta-1,4.