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Nitrocellulose film on a light box, showing deterioration, from Library and Archives Canada collection. In 1855, the first human-made plastic, nitrocellulose (branded Parkesine, patented in 1862), was created by Alexander Parkes from cellulose treated with nitric acid and a solvent.
Celluloids are a class of materials produced by mixing nitrocellulose and camphor, often with added dyes and other agents.Once much more common for its use as photographic film before the advent of safer methods, celluloid's common present-day uses are for manufacturing table tennis balls, musical instruments, combs, office equipment, fountain pen bodies, and guitar picks.
Some animals, particularly ruminants and termites, can digest cellulose with the help of symbiotic micro-organisms that live in their guts, such as Trichonympha. In human nutrition , cellulose is a non-digestible constituent of insoluble dietary fiber , acting as a hydrophilic bulking agent for feces and potentially aiding in defecation .
Possible remains of biotic life were found in 4.1 billion-year-old rocks in Western Australia. [26] [27] Probable origin of life. 4000 Ma Formation of a greenstone belt of the Acasta Gneiss of the Slave craton in northwest Canada - the oldest known rock belt. [28] 3900–2500 Ma Cells resembling prokaryotes appear. [29]
As duplex DNA became the predominant form of the genetic material, the mechanism of genetic recovery evolved into the more complex process of meiotic recombination, found today in most species. It thus appears likely that sexual reproduction arose early in the evolution of cells and has had a continuous evolutionary history.
Nitrocellulose is a derivative of cellulose that is soluble in organic solvents. It is mainly used as an explosive or as a lacquer. Many early plastics, including celluloid, were made from nitrocellulose. Cellulose acetate shares many traits with viscose rayon and was formerly considered the same textile. However, rayon resists heat, while ...
The original production process uses carbon disulfide (CS 2), which has been found to be highly toxic to workers. [2] The newer lyocell process can be used to produce cellulose film without involving carbon disulfide. [3] "Cellophane" is a generic term in some countries, [4] while in other countries it is a registered trademark.
Ribbon representation of the Streptomyces lividans β-1,4-endoglucanase catalytic domain - an example from the family 12 glycoside hydrolases [1]. Cellulase (EC 3.2.1.4; systematic name 4-β-D-glucan 4-glucanohydrolase) is any of several enzymes produced chiefly by fungi, bacteria, and protozoans that catalyze cellulolysis, the decomposition of cellulose and of some related polysaccharides: