In 1838, a French chemist named Anselme Payen discovered cellulose. Payen actually separated cellulose from plant material and decided on the chemical formula of the substance. In 1870, Hyatt Manufacturing Company was successful for the first time to produce thermoplastic polymer, also known as celluloid. In 1920, German scientist Hermann Staudinger, who won the Nobel Prize in chemistry, first established the polymer structure of cellulose. In fact, Shiro Kobayashi and Shin-ichiro Shoda were the first to chemically synthesize cellulose in 1992.
Cellulose is basically a molecule enclosing carbon, oxygen and hydrogen and is present in the cellular arrangement of practically every plant matter. It is an organic compound that is deemed to be present on the earth most abundantly and, interesting enough, it is also oozed out by a number of bacteria.
Cellulose actually imparts strength and structure to the walls of the plant cells and supplies fiber in our foods. While a number of animals, for instance ruminants are able to digest or absorb cellulose, humans do not possess this aptitude. Hence, cellulose is categorized as indigestible carbohydrates, also called dietary fiber.
A linear polysaccharide polymer, cellulose contains several units of glucose monosaccharide. The acetal connection of cellulose is beta that differentiates this organic compound from starch. Such a peculiar dissimilarity in acetal relation leads to a major disparity in digestibility in humans. Basically, humans are not able to absorb cellulose into their body owing to the lack of suitable enzymes to metabolize the beta acetal linkages. Indigestible cellulose is actually the fiber that facilitates in the efficient and trouble-free functioning of the intestinal tract.
The intestinal tract of animals, for instance cows, sheep, goats, horse as well as termites possess symbiotic bacteria. Such symbiotic bacteria have the requisite enzymes need to absorb or digest cellulose in their gastrointestinal (GI) tract. In addition, they also possess the needed enzymes for breaking down or hydrolysis of cellulose. However, other animals, do not possess the appropriate enzymes. Precisely speaking, no vertebrate has the capacity to digest cellulose in its original form or directly.
While we are unable to digest cellulose, we are likely to find several utilities for this organic compound, for instance wood for construction, cotton, rayon and linen for clothes, wood for paper products, cellulose acetate for making films, and nitrocellulose for explosives.
Human uses of cellulose
It may be noted that cellulose is among the most extensively utilized natural substances and has turned out to be among the most vital commercial raw materials available. There are several resources of cellulose, major among them are plant cellulose, for instance cotton, flax, hemp and jute, and, definitely, wood, which supplies approximately 43 per cent of cellulose. As cellulose is not soluble in water, it is easy to separate this organic compound from other integral elements of any plant.
Ever since the Chinese invented the process of paper making from cellulose in 100 A.D., this organic compound has been extensively used for the purpose. Cellulose is isolated from wood by means of a process known as pulping, wherein the wooden chips are grinded under running water. The pulp left behind is rinsed, bleached and poured on top of a vibrating net. After the water present in the pulp has been completely drained out, what is left behind is actually an interlocking mesh of fibers, which transforms into a sheet of paper after the fibers are dried out, compressed and smoothed.
Unprocessed cotton contains about 91 per cent cellulose and the fiber cells of raw cotton are present on the exterior of the cotton seed. In effect, each cotton seed has several thousand fibers and when the cotton pod matures and explodes, all these fiber cells die. As these fiber cells are basically cellulose, it is possible to twist them to shape them into threat or yarn, which is subsequently woven to manufacture cloth. Cellulose easily reacts to strong bases as well as acids and, therefore, often a chemical procedure is employed to manufacture other products from cellulose. For instance, the fabric that we all call rayon and the see-through sheet of film which is called cellophane are produced by employing a multiple-step process that entails an acid bath.
Cellulose has the aptitude to form a substance called cellulose nitrates or guncotton in mixtures of sulfuric acids and nitric acids, which are used in the manufacture of explosives. Nevertheless, when cellulose is mixed with camphor, it produces plastic called celluloid, which was once used as film for motion-picture. Then again, since cellulose was an extremely flammable substance that could catch fire easily, ultimately it was substituted by more latest and consistent plastic materials. While cellulose continues to remain a vital natural resource, several products made from this organic compound earlier are today being produced using other substances and they are comparatively easier to make as well as inexpensive.
Several other by-products of cellulose are employed in the form of adhesives, to thicken foods, to manufacture explosives as well as in damp-proof coatings.
Importance to human diet
Notwithstanding the fact that cellulose cannot be digested by humans as well as several other animals as their digestive systems do not possess the ability to breakdown this organic compound into its fundamental elements and absorb them in their body, cellulose still forms a very vital part of human diet. This is primarily owing to the fact that cellulose forms an important part of the dietary fiber, which we all are aware, is essential for appropriate digestion of our food. As we are unable to disintegrate or break down cellulose while it goes through our systems mostly unaltered. Therefore, cellulose works in a way what we know as bulk or roughage that facilitates every intestinal movement.
It is only the ruminants among animals that have the ability to break down and digest cellulose. These cud chewing animals include cows and horses. They are able to digest cellulose since they possess microorganisms, including bacteria, in their digestive tracts that make it possible to absorb cellulose. As a result of this, these animals can absorb the disintegrated cellulose and utilize the sugar enclosed by it in the form of a food source. In effect, fungi too have the aptitude to break down cellulose into its primary elements, mainly sugar, which they are able to soak up. Therefore, it is known that fungi play a vital role in decaying or rotting of wood as well as other plant substances.