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Cellulose is used to make water-soluble adhesives and binders such as methyl cellulose and carboxymethyl cellulose which are used in wallpaper paste. Cellulose is further used to make hydrophilic and highly absorbent sponges. Cellulose is the raw material in the manufacture of nitrocellulose (cellulose nitrate) which is used in smokeless gunpowder.
Structure of xylan in hardwood. [1] Plant cell wall is composed of cellulose, hemicellulose, pectin and glycoproteins. [2] Hemicelluloses (a heterogeneous group of polysaccharides) cross-link glycans interlocking the cellulose fibers and form a mesh like structure to deposit other polysaccharides.
Cellulose is a polymer made of repeating glucose molecules attached end to end. [4] A cellulose molecule may be from several hundred to over 10,000 glucose units long. Cellulose is similar in form to complex carbohydrates like starch and glycogen. These polysaccharides are also made from multiple subunits of glucose.
In contrast, each polymer of cellulose comprises 7,000–15,000 glucose molecules. [5] In addition, hemicelluloses may be branched polymers, while cellulose is unbranched. Hemicelluloses are embedded in the cell walls of plants, sometimes in chains that form a 'ground' – they bind with pectin to cellulose to form a network of cross-linked fibres.
Cellulose is a polymer made with repeated glucose units bonded together by beta-linkages. Humans and many animals lack an enzyme to break the beta-linkages, so they do not digest cellulose. Certain animals, such as termites can digest cellulose, because bacteria possessing the enzyme are present in their gut. Cellulose is insoluble in water.
The Thermotoga maritima species make cellulases consisting of 2 β-sheets (protein structures) surrounding a central catalytic region which is the active-site. [10] The enzyme is categorised as an endoglucanase, which internally cleaves β-1,4-glycosydic bonds in cellulose chains facilitating further degradation of the polymer.
Biopolymers often have a well-defined structure, though this is not a defining characteristic (example: lignocellulose): The exact chemical composition and the sequence in which these units are arranged is called the primary structure, in the case of proteins.
Cellulose microfibrils are made on the surface of cell membranes to reinforce cells walls, which has been researched extensively by plant biochemists and cell biologist because 1) they regulate cellular morphogenesis and 2) they serve alongside many other constituents (i.e. lignin, hemicellulose, pectin) in the cell wall as a strong structural support and cell shape. [15]