Cellulose
Cellulose is an organic compound and the most abundant biopolymer on Earth. It is a complex carbohydrate, or polysaccharide, consisting of 3,000 or more glucose units[2]. The basic structural component of plant cell walls, cellulose comprises about 33 percent of all vegetable matter (90 percent of cotton and 50 percent of wood are cellulose) and is the most abundant of all naturally occurring organic compounds[2].
The structure of cellulose consists of long polymer chains of glucose units connected by a beta acetal linkage[10]. This linkage motif contrasts with that for alpha(1→4)-glycosidic bonds present in starch and glycogen, making cellulose a straight chain polymer[1]. Unlike starch, no coiling or branching occurs, and the molecule adopts an extended and fibrous structure[1]. The chemical formula of cellulose is (C6H10O5)n where n is the degree of polymerization and represents the number of glucose units[1].
Cellulose is synthesized at the plasma membrane by rosette terminal complexes (RTCs) in plants[1]. These RTCs are hexameric protein structures that contain the cellulose synthase enzymes that synthesize the individual cellulose chains[1].
In terms of its properties, cellulose is insoluble in water and most organic solvents, is biodegradable, and chiral[7]. It has a high tensile strength due to the hydrogen bonds formed between the glucose chains[7]. Cellulose from wood pulp has typical chain lengths between 300 and 1700 units; cotton and other plant fibers as well as bacterial cellulose have chain lengths ranging from 800 to 10,000 units[1].
Cellulose has numerous applications. It is processed to produce papers and fibers and is chemically modified to yield substances used in the manufacture of items such as plastics, photographic films, and rayon[2]. Other cellulose derivatives are used as adhesives, explosives, thickening agents for foods, and in moisture-proof coatings[2].
In the diet, cellulose acts as an insoluble fiber that aids in digestion by helping to push food through the digestive system and support regular bowel movements[3]. It is also used as a food additive in products like shredded cheese and ice creams to prevent clumping and to provide thickness[3].
Cellulose is also of high technological interest due to its ability to form nanocelluloses, which have superior thermal and mechanical properties and can be used in nanocomposites, hydrogels, or aerogels[1].
In summary, cellulose is a vital natural polymer with a wide range of applications in various industries, from paper and textiles to food and nanotechnology.
Citations:
[1] https://en.wikipedia.org/wiki/Cellulose
[2] https://www.britannica.com/science/cellulose
[3] https://www.healthline.com/nutrition/cellulose-fiber
[4] https://pubchem.ncbi.nlm.nih.gov/compound/Cellulose
[5] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8704128/
[6] https://www.researchgate.net/publication/283447497_Sources_of_cellulose_and_their_applications-_A_review
[7] https://byjus.com/chemistry/cellulose/
[8] https://link.springer.com/article/10.1007/s10570-020-03674-w
[9] https://cellulogyx.com/sources-of-cellulose/
[10] https://chem.libretexts.org/Bookshelves/Biological_Chemistry/Supplemental_Modules_%28Biological_Chemistry%29/Carbohydrates/Polysaccharides/Cellulose
[11] https://www.thoughtco.com/what-is-cellulose-definition-4777807
[12] https://link.springer.com/chapter/10.1007/978-3-319-73168-1_1
[13] https://alevelbiology.co.uk/notes/cellulose/
[14] https://www.papertr.com/use-of-cellulose/
[15] https://link.springer.com/chapter/10.1007/12_2015_319
[16] https://www.linkedin.com/pulse/what-most-important-use-cellulose-kima-chemical-zibo-co-ltd-hglic
[17] https://study.com/academy/lesson/cellulose-in-plants-function-structure-quiz.html
[18] https://www.snexplores.org/article/lets-learn-about-cellulose
[19] https://www.intechopen.com/chapters/67083