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Diastase
A diastase (; from Greek διάστασις, "separation") is any one of a group of enzymes that catalyses the breakdown of starch into maltose. For example, the diastase α-amylase degrades starch to a mixture of the disaccharide maltose; the trisaccharide maltotriose, which contains three α (1-4)-linked glucose residues; and oligosaccharides, known as dextrins, that contain the α (1-6)-linked glucose branches. Diastase was the first enzyme discovered. It was extracted from malt solution in 1833 by Anselme Payen and Jean-François Persoz, chemists at a French sugar factory. The name "diastase" comes from the Greek word διάστασις (''diastasis'') (a parting, a separation), because when beer mash is heated, the enzyme causes the starch in the barley seed to transform quickly into soluble sugars and hence the husk to separate from the rest of the seed. Today, "diastase" refers to any α-, β-, or γ-amylase (all of which are hydrolases) that can break down carbohydra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periodic Acid–Schiff Stain
Periodic acid–Schiff (PAS) is a staining method used to detect polysaccharides (such as glycogen) and mucosubstances (such as glycoproteins, glycolipids and mucins) in tissues. The reaction of periodic acid oxidizes vicinal diols in these sugars, usually breaking up the bond between two adjacent carbons not involved in the glycosidic linkage or ring closure in the ring of monosaccharide units that are part of the long polysaccharides and creating a pair of aldehydes at the two free tips of each broken monosaccharide ring. The oxidation condition has to be sufficiently regulated so as to not further oxidize the aldehydes. These aldehydes then react with the Schiff reagent to give a purple-magenta color. A suitable basic stain is often used as a counterstain. • PAS diastase stain (PAS-D) is PAS stain used in combination with diastase, an enzyme that breaks down glycogen. • Alcian blue/periodic acid–Schiff (AB/PAS or AB-PAS) uses alcian blue before the PAS step. Uses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Takadiastase
Takadiastase is a form of diastase which results from the growth, development, and nutrition of a distinct microscopic fungus known as ''Aspergillus oryzae'' (Koji). Takadiastase is named after Jōkichi Takamine, who developed the method first used for its extraction. External links Jokichi Takamine Taka-Diastase, AdrenalineHistory of industrial property rights (Japan Patent Office The is a Japanese governmental agency in charge of industrial property right affairs, under the Ministry of Economy, Trade and Industry. The Japan Patent Office is located in Kasumigaseki, Chiyoda, Tokyo and is one of the world's largest pa ...) Development of Takadiastase Hydrolases {{Enzyme-stub ja:ジアスターゼ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anselme Payen
Anselme Payen (; 6 January 1795 – 12 May 1871) was a French chemist known for discovering the enzyme diastase, and the carbohydrate cellulose. Biography Payen was born in Paris. He began studying science with his father when he was a 13-year-old, and later studied Chemistry at the École Polytechnique under the chemists Louis Nicolas Vauquelin and Michel Eugène Chevreul. At the age of 23, Payen became manager of a borax-refining factory, where he developed a process for synthesizing borax from soda and boric acid. Previously, all borax had been imported from the East Indies exclusively by the Dutch. Payen's new method of synthesizing borax allowed him to sell the mineral at one third the going price, and break the Dutch monopoly. Payen also developed processes for refining sugar, along with a way to refine starch and alcohol from potatoes, and a method for determination of nitrogen. Payen invented a decolorimeter, which dealt with the analysis, decolorization, bleaching, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), 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, 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 include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jean-François Persoz
Jean-François Persoz (9 June 1805–September 1868) was a French chemist known for discovering the enzyme diastase and on the properties of dextrin. He also wrote a report that coined the name cellulose. Born in Cortaillod, Persoz studied physical science in Paris under Louis Jacques Thénard and received his doctorate in 1833. Persoz was a professor of chemistry at the University of Strasbourg since 1833 and then a professor of dyeing and calico-printing at the Conservatoire des Arts et Metiers since 1852. His work on diastase, also known as amylase, was carried out in collaboration with Anselme Payen Anselme Payen (; 6 January 1795 – 12 May 1871) was a French chemist known for discovering the enzyme diastase, and the carbohydrate cellulose. Biography Payen was born in Paris. He began studying science with his father when he was a 13-yea ... and published in 1833. His work on dextrin was carried out in collaboration with J.B. BiotBiot, J. B., Persoz, J.: Ann. Chim. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amylase
An amylase () is an enzyme that catalysis, catalyses the hydrolysis of starch (Latin ') into sugars. Amylase is present in the saliva of humans and some other mammals, where it begins the chemical process of digestion. Foods that contain large amounts of starch but little sugar, such as rice and potatoes, may acquire a slightly sweet taste as they are chewed because amylase degrades some of their starch into sugar. The pancreas and salivary gland make amylase (alpha amylase) to hydrolyse dietary starch into disaccharides and trisaccharides which are converted by other enzymes to glucose to supply the body with energy. Plants and some bacteria also produce amylase. Specific amylase proteins are designated by different Greek letters. All amylases are glycoside hydrolases and act on α-1,4-glycosidic bonds. Classification α-Amylase The α-amylases () (CAS registry number, CAS 9014–71–5) (alternative names: 1,4-α-D-glucan glucanohydrolase; glycogenase) are calcium metallop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
-ase
The suffix -ase is used in biochemistry to form names of enzymes. The most common way to name enzymes is to add this suffix onto the end of the substrate, ''e.g.'' an enzyme that breaks down peroxides may be called peroxidase; the enzyme that produces telomeres is called telomerase. Sometimes enzymes are named for the function they perform, rather than substrate, e.g. the enzyme that polymerizes (assembles) DNA into strands is called polymerase; see also reverse transcriptase. Etymology The ''-ase'' suffix is a libfix derived from " diastase", the first recognized enzyme. Its usage in subsequently discovered enzymes was proposed by Émile Duclaux, with the intention of honoring the first scientists to isolate diastase. See also *Amylase *DNA polymerase A DNA polymerase is a member of a family of enzymes that catalyze the synthesis of DNA molecules from nucleoside triphosphates, the molecular precursors of DNA. These enzymes are essential for DNA replication and usually wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whipple Disease
Whipple's disease is a rare systemic infectious disease caused by the bacterium '' Tropheryma whipplei''. First described by George Hoyt Whipple in 1907 and commonly considered as a gastrointestinal disorder, Whipple's disease primarily causes malabsorption, but may affect any part of the human body, including the heart, brain, joints, skin, lungs and the eyes. Weight loss, diarrhea, joint pain, and arthritis are common presenting symptoms, but the presentation can be highly variable in certain individuals, and about 15% of patients do not have the standard signs and symptoms. Whipple's disease is significantly more common in men, with 87% of patients diagnosed being male. When recognized and treated, Whipple's disease can usually be cured with long-term antibiotic therapy, but if the disease is left undiagnosed or untreated, it can ultimately be fatal. Signs and symptoms The most common symptoms are diarrhea, abdominal pain, weight loss, and joint pains. The joint pains may b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Émile Duclaux
Émile Duclaux (24 June 1840 – May 2, 1904) was a French microbiologist and chemist born in Aurillac, Cantal. He studied at the College of Aurillac, the Lycée Saint-Louis in Paris and at École Normale Supérieure. In 1862 he began work as an assistant in the laboratory of Louis Pasteur (1822–1895). During his career, he taught classes in Tours (1865), Clermont-Ferrand (1866), Lyon (from 1873) and Paris (from 1878). In Paris, he was a professor of meteorology at the Institute of Agronomy. For much of his career he was associated with the work of Louis Pasteur. In 1888 he was elected to the ''Académie des sciences'', and in 1894 became a member of the '' Académie Nationale de Médecine''. Duclaux's work was largely in the fields of chemistry, bacteriology, hygiene and agriculture. Duclaux initiated the custom of naming enzymes by adding the suffix "-ase" to the enzyme's substrate. His intention was to honor the first scientists (namely Anselme Payen, 1795–1871; and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ATC Code
The Anatomical Therapeutic Chemical (ATC) Classification System is a drug classification system that classifies the active ingredients of drugs according to the organ or system on which they act and their therapeutic, pharmacological and chemical properties. Its purpose is an aid to monitor drug use and for research to improve quality medication use. It does not imply drug recommendation or efficacy. It is controlled by the World Health Organization Collaborating Centre for Drug Statistics Methodology (WHOCC), and was first published in 1976. Coding system This pharmaceutical coding system divides drugs into different groups according to the organ or system on which they act, their therapeutic intent or nature, and the drug's chemical characteristics. Different brands share the same code if they have the same active substance and indications. Each bottom-level ATC code stands for a pharmaceutically used substance, or a combination of substances, in a single indication (or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jaundice
Jaundice, also known as icterus, is a yellowish or, less frequently, greenish pigmentation of the skin and sclera due to high bilirubin levels. Jaundice in adults is typically a sign indicating the presence of underlying diseases involving abnormal heme metabolism, liver dysfunction, or biliary-tract obstruction. The prevalence of jaundice in adults is rare, while jaundice in babies is common, with an estimated 80% affected during their first week of life. The most commonly associated symptoms of jaundice are itchiness, pale feces, and dark urine. Normal levels of bilirubin in blood are below 1.0 mg/ dl (17 μmol/ L), while levels over 2–3 mg/dl (34–51 μmol/L) typically result in jaundice. High blood bilirubin is divided into two types: unconjugated and conjugated bilirubin. Causes of jaundice vary from relatively benign to potentially fatal. High unconjugated bilirubin may be due to excess red blood cell breakdown, large bruises, gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
