|
Zymase
Zymase is an enzyme complex that catalyzes the fermentation of sugar into ethanol and carbon dioxide. It occurs naturally in yeasts. Zymase activity varies among yeast strains. Zymase is also the brand name of the drug pancrelipase. Cell-free fermentation experiment Zymase was first isolated from the yeast cell in 1897 by a German chemist named Eduard Buchner who fermented sugar in the laboratory without living cells, leading to 1907 Nobel Prize in Chemistry. The experiment for which Buchner won the Nobel Prize consisted of producing a cell-free extract of yeast cells and showing that this "press juice" could ferment sugar. This dealt yet another blow to vitalism by showing that the presence of living yeast cells was not needed for fermentation. The cell-free extract was produced by combining dry yeast cells, quartz and kieselguhr and then pulverizing the yeast cells with a mortar and pestle. This mixture would then become moist as the yeast cells' contents would come out of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar. Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation from α-quartz to β-quartz takes place abruptly at . Since the transformation is accompanied by a significant change in volume, it can easily induce microfracturing of ceramics or rocks passing through this temperature threshold. There are many different varieties of quartz, several of which are classified as gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Eurasia. Quartz is the mineral defining the val ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antoine Béchamp
Pierre Jacques Antoine Béchamp (16 October 1816 – 15 April 1908) was a French scientist now best known for breakthroughs in applied organic chemistry and for a bitter rivalry with Louis Pasteur. Béchamp developed the Béchamp reduction, an inexpensive method to produce aniline dye, permitting William Henry Perkin to launch the synthetic-dye industry. Béchamp also synthesized the first organic arsenical drug, arsanilic acid, from which Paul Ehrlich later synthesized salvarsan, the first chemotherapeutic drug. Béchamp's rivalry with Pasteur was initially for priority in attributing fermentation to microorganisms, later for attributing the silkworm disease pebrine to microorganisms, and eventually over the validity of germ theory. Béchamp claimed to have discovered that the "molecular granulations" in biological fluids were actually the elementary units of life. He named them ''microzymas''—that is, "tiny enzymes"—and credited them with producing both enzymes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthur Harden
Sir Arthur Harden, FRS (12 October 1865 – 17 June 1940) was a British biochemist. He shared the Nobel Prize in Chemistry in 1929 with Hans Karl August Simon von Euler-Chelpin for their investigations into the fermentation of sugar and fermentative enzymes. He was a founding member of the Biochemical Society and editor of its journal for 25 years. Biography Early years Arthur was born to Scottish Presbyterian businessman Albert Tyas Harden and Eliza Macalister. His early education was at a private school in Victoria Park run by Dr Ernest Adam. He went to study in 1877 at a Tettenhall College, Staffordshire, and entered Owens College in 1882, now the University of Manchester, in 1882, graduating in 1885. He studied chemistry under Professor Roscoe at Owens College and was influenced by J.B. Cohen. Research In 1886 Harden was awarded the Dalton Scholarship in Chemistry and spent a year working with Otto Fischer at Erlangen where he worked on the synthesis of β-nitroso-α-napht ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maltose
} Maltose ( or ), also known as maltobiose or malt sugar, is a disaccharide formed from two units of glucose joined with an α(1→4) bond. In the isomer isomaltose, the two glucose molecules are joined with an α(1→6) bond. Maltose is the two-unit member of the amylose homologous series, the key structural motif of starch. When beta-amylase breaks down starch, it removes two glucose units at a time, producing maltose. An example of this reaction is found in germinating seeds, which is why it was named after malt. Unlike sucrose, it is a reducing sugar. History Maltose was discovered by Augustin-Pierre Dubrunfaut, although this discovery was not widely accepted until it was confirmed in 1872 by Irish chemist and brewer Cornelius O'Sullivan. Its name comes from malt, combined with the suffix ' -ose' which is used in names of sugars. Structure and nomenclature Carbohydrates are generally divided into monosaccharides, oligosaccharides, and polysaccharides depending on the nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fructose
Fructose, or fruit sugar, is a Ketose, ketonic monosaccharide, simple sugar found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed by the gut directly into the blood of the portal vein during digestion. The liver then converts both fructose and galactose into glucose, so that dissolved glucose, known as blood sugar, is the only monosaccharide present in circulating blood. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847. The name "fructose" was coined in 1857 by the English chemist William Allen Miller. Pure, dry fructose is a sweet, white, odorless, crystalline solid, and is the most water-soluble of all the sugars. Fructose is found in honey, tree and vine fruits, flowers, Berry, berries, and most List of root vegetables, root vegetables. Commercially, fructose is derived from sugar cane, sugar beets, and maize. Hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucose
Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using energy from sunlight, where it is used to make cellulose in cell walls, the most abundant carbohydrate in the world. In energy metabolism, glucose is the most important source of energy in all organisms. Glucose for metabolism is stored as a polymer, in plants mainly as starch and amylopectin, and in animals as glycogen. Glucose circulates in the blood of animals as blood sugar. The naturally occurring form of glucose is -glucose, while -glucose is produced synthetically in comparatively small amounts and is less biologically active. Glucose is a monosaccharide containing six carbon atoms and an aldehyde group, and is therefore an aldohexose. The glucose molecule can exist in an open-chain (acyclic) as well as ring (cyclic) form. Gluco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kieselguhr
Diatomaceous earth (), diatomite (), or kieselgur/kieselguhr is a naturally occurring, soft, siliceous sedimentary rock that can be crumbled into a fine white to off-white powder. It has a particle size ranging from more than 3 μm to less than 1 mm, but typically 10 to 200 μm. Depending on the granularity, this powder can have an abrasive feel, similar to pumice powder, and has a low density as a result of its high porosity. The typical chemical composition of oven-dried diatomaceous earth is 80–90% silica, with 2–4% alumina (attributed mostly to clay minerals), and 0.5–2% iron oxide. Diatomaceous earth consists of the fossilized remains of diatoms, a type of hard-shelled microalgae. It is used as a filtration aid, mild abrasive in products including metal polishes and toothpaste, mechanical insecticide, absorbent for liquids, matting agent for coatings, reinforcing filler in plastics and rubber, anti-block in plastic films, porous support for chemica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitalism
Vitalism is a belief that starts from the premise that "living organisms are fundamentally different from non-living entities because they contain some non-physical element or are governed by different principles than are inanimate things." Where vitalism explicitly invokes a vital principle, that element is often referred to as the "vital spark," "energy," or "''élan vital''," which some equate with the soul. In the 18th and 19th centuries vitalism was discussed among biologists, between those who felt that the known mechanics of physics would eventually explain the difference between life and non-life and vitalists who argued that the processes of life could not be reduced to a mechanistic process. Vitalist biologists such as Johannes Reinke proposed testable hypotheses meant to show inadequacies with mechanistic explanations, but their experiments failed to provide support for vitalism. Biologists now consider vitalism in this sense to have been refuted by empirical evidence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalysis
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst. Catalysis may be classified as either homogeneous, whose components are dispersed in the same phase (usually gaseous or liquid) as the reactant, or heterogeneous, whose components are not in the same phase. Enzymes and other biocatalysts are often considered as a third category. Catalysis is ubiquitous in chemical industry of all kinds. Estimates are that 90% of all commercially produced chemical products involve catalysts at some s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eduard Buchner
Eduard Buchner (; 20 May 1860 – 13 August 1917) was a German chemist and zymologist, awarded the 1907 Nobel Prize in Chemistry for his work on fermentation. Biography Early years Buchner was born in Munich to a physician and Doctor Extraordinary of Forensic Medicine. His older brother was Hans Ernst August Buchner. In 1884, he began studies of chemistry with Adolf von Baeyer and of botany with Carl Nägeli, at the Botanic Institute in Munich. After a period working with Otto Fischer (cousin of Emil Fischer) at the University of Erlangen, Buchner was awarded a doctorate from the University of Munich in 1888 under Theodor Curtius. Academics Buchner was appointed assistant lecturer in the organic laboratory of Adolf von Baeyer in 1889 at the University of Munich. In 1891, he was promoted to lecturer at the same university. In the autumn of 1893, Buchner moved to University of Kiel and appointed professor in 1895. In the next year he was appointed Professor Extraordinary for A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pancrelipase
Pancreatic enzymes, also known as pancreases or pancrelipase and pancreatin, are commercial mixtures of amylase, lipase, and protease. They are used to treat malabsorption syndrome due to certain pancreatic problems. These pancreatic problems may be due to cystic fibrosis, surgical removal of the pancreas, long term pancreatitis, or pancreatic cancer, among others. The preparation is taken by mouth. Common side effects include vomiting, abdominal pain, constipation, and diarrhea. Other side effects include perianal irritation and high blood uric acid. The enzymes are from pigs. Use is believed to be safe during pregnancy. The components are digestive enzymes similar to those normally produced by the human pancreas. They help the person digest fats, starches, and proteins. Pancreatic enzymes have been used as medications since at least the 1800s. They are on the World Health Organization's List of Essential Medicines. In 2020, it was the 262nd most commonly prescribed me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
