What type of bonding allows cellulose to form sheets?

Cellulose is a polysaccharide that consists of long chains of β-D-glucose units linked by β(1→4) glycosidic bonds. The structural integrity of cellulose arises from the ability of its molecules to interact with one another through hydrogen bonding.

Cellulose chains can form extensive networks by creating hydrogen bonds between hydroxyl (-OH) groups on adjacent chains. This intramolecular and intermolecular hydrogen bonding results in the formation of microfibrils, which are basic structural units of cellulose. These microfibrils bundle together to form larger fibers, contributing to the rigidity and strength of plant cell walls.

Covalent bonds primarily hold the glucose units together within the cellulose polymer chain, but they do not contribute to the sheet-like structure. Ionic bonds are not relevant in the context of cellulose structure, as they typically involve charged entities rather than the neutral functional groups present in cellulose. Disulfide bonds, which play a critical role in stabilizing protein structures by forming links between cysteine residues, have no significance in the structure of cellulose.

Thus, the prevalence of hydrogen bonding is crucial for the formation of sheets in cellulose, providing the necessary structural stability and mechanical strength for plant tissues.