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Isolichenan
Isolichenan, also known as isolichenin, is a cold-water-soluble alpha glucan, α-glucan occurring in certain species of lichens. This lichen product was first isolated as a component of an extract of Cetraria islandica, Iceland moss in 1813, along with lichenin. After further analysis and characterization of the individual components of the extract, isolichenan was named in 1881. It is the first α-glucan to be described from lichens. The presence of isolichenan in the cell walls is a defining characteristic in several genus, genera of the lichen family Parmeliaceae. Although most prevalent in that family (biology), family, it has also been isolated from members of the families Ramalinaceae, Stereocaulaceae, Roccellaceae, and Cladoniaceae. Experimental studies have shown that isolichenan is produced only when the two lichen components – fungus and alga – are growing together, not when grown separately. The biological function of isolichenan in the lichen thallus is unknown. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parmeliaceae
The Parmeliaceae is a large and diverse family of Lecanoromycetes. With over 2700 species in 71 genera, it is the largest family of lichen-forming fungi. The most speciose genera in the family are the well-known groups: '' Xanthoparmelia'' ( 822 species), ''Usnea'' (355 species), ''Parmotrema'' ( 255 species), and ''Hypotrachyna'' (262 species). Nearly all members of the family have a symbiotic association with a green alga (most often ''Trebouxia'' spp., but '' Asterochloris'' spp. are known to associate with some species).Miadlikowska, J. ''et al.'' (2006). New insights into classification and evolution of the Lecanoromycetes (Pezizomycotina, Ascomycota) from phylogenetic analyses of three ribosomal RNA- and two protein-coding genes. ''Mycologia'' 98: 1088-1103. http://www.mycologia.org/cgi/reprint/98/6/1088.pdf The majority of Parmeliaceae species have a foliose, fruticose, or subfruticose growth form. The morphological diversity and complexity exhibited by this group is en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lichen Product
Lichen products, also known as lichen substances, are organic compounds produced by a lichen. Specifically, they are secondary metabolites. Lichen products are represented in several different chemical classes, including terpenoids, orcinol derivatives, chromones, xanthones, depsides, and depsidones. Over 800 lichen products of known chemical structure have been reported in the scientific literature, and most of these compound are exclusively found in lichens. Examples of lichen products include usnic acid (a dibenzofuran), atranorin (a depside), lichexanthone (a xanthone), salazinic acid (a depsidone), and isolichenan, an α-glucan. Many lichen products have biological activity, and research into these effects is ongoing. Lichen products accumulate on the outer walls of the fungal hyphae, and are quite stable. Crystal deposits can be visualised using scanning electron microscopy. For this reason, even very old herbarium specimens can be analysed. The amount of lichen products i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Glucan
α-Glucans (alpha-glucans) are polysaccharides of D-glucose monomers linked with glycosidic bonds of the alpha form. α-Glucans use cofactors in a cofactor site in order to activate a glucan phosphorylase enzyme. This enzyme causes a reaction that transfers a glucosyl portion between orthophosphate and α-I,4-glucan. The position of the cofactors to the active sites on the enzyme are critical to the overall reaction rate thus, any alteration to the cofactor site leads to the disruption of the glucan binding site. Alpha-glucan is also commonly found in bacteria, yeasts, plants, and insects. Whereas the main pathway of α-glucan synthesis is via glycosidic bonds of glucose monomers, α-glucan can be comparably synthesized via the maltosyl transferase GlgE and branching enzyme GlgB. This alternative pathway is common in many bacteria, which use GlgB and GlgE or the GlgE pathway exclusively for the biosynthesis of α-glucan. The GlgE pathway is especially prominent in actinomycetes, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jöns Jacob Berzelius
Baron Jöns Jacob Berzelius (; by himself and his contemporaries named only Jacob Berzelius, 20 August 1779 – 7 August 1848) was a Swedish chemist. Berzelius is considered, along with Robert Boyle, John Dalton, and Antoine Lavoisier, to be one of the founders of modern chemistry. Berzelius became a member of the Royal Swedish Academy of Sciences in 1808 and served from 1818 as its principal functionary. He is known in Sweden as the "Father of Swedish Chemistry". Berzelius Day is celebrated on 20 August in honour of him. Although Berzelius began his career as a physician, his enduring contributions were in the fields of electrochemistry, chemical bonding and stoichiometry. In particular, he is noted for his determination of atomic weights and his experiments that led to a more complete understanding of the principles of stoichiometry, which is the branch of chemistry pertaining to the quantitative relationships between elements in chemical compounds and chemical reactions and ... [...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] |
Polymer
A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compounds, produces unique physical properties including toughness, high elasticity, viscoelasticity, and a tendency to form amorphous and semicrystalline structures rather than crystals. The term "polymer" derives from the Greek word πολύς (''polus'', meaning "many, much") and μέρος (''meros'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yield (chemistry)
In chemistry, yield, also referred to as reaction yield, is a measure of the quantity of Mole (unit), moles of a Product (chemistry), product formed in relation to the reactant consumed, obtained in a chemical reaction, usually expressed as a percentage. Yield is one of the primary factors that scientists must consider in organic synthesis, organic and inorganic chemical synthesis processes. In chemical reaction engineering, "yield", "Conversion (chemistry), conversion" and "selectivity" are terms used to describe ratios of how much of a reactant was consumed (conversion), how much desired product was formed (yield) in relation to the undesired product (selectivity), represented as X, Y, and S. Definitions In chemical reaction engineering, "yield", "Conversion (chemistry), conversion" and "selectivity" are terms used to describe ratios of how much of a reactant has reacted—conversion, how much of a desired product was formed—yield, and how much desired product was formed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mother Liquor
The mother liquor (or spent liquor) is the solution Solution may refer to: * Solution (chemistry), a mixture where one substance is dissolved in another * Solution (equation), in mathematics ** Numerical solution, in numerical analysis, approximate solutions within specified error bounds * Soluti ... remaining after a component has been removed by a some process such as filtration or more commonly crystallization. It is encountered in chemical processes including sugar refining. In crystallization, a solid (usually impure) is dissolved in a solvent at high temperature, taking advantage of the fact that most solids are more soluble at higher temperatures. As the solution cools, the solubility of the solute in the solvent will gradually become smaller. The resultant solution is described as supersaturated, meaning that there is more solute dissolved in the solution than would be predicted by its solubility at that temperature. Crystallization can then be induced from this supe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kurt Heinrich Meyer
Kurt Heinrich Meyer or Kurt Otto Hans Meyer (29 September 1883 – 14 April 1952) was a German chemist. Life and work Born in Tartu, Estonia, Meyer was the son of the pharmacologist Hans Horst Meyer. He was a student from 1892 until 1901 in the “Gymnasium Philippinum” in Marburg, Germany. This was followed at first by studies in medicine, later in chemistry in Marburg (where Theodor Zincke was the professor), and in Leipzig, Freiburg, London, and Munich. In Leipzig, Meyer obtained his PhD in 1907 with the dissertation “Untersuchungen über Halochromie” (Research on Halochromie) under the direction of Arthur Hantzsch. Afterwards, following the advice of his father, he travelled to England to complement his education and worked for several months in the laboratory of Ernest Rutherford. After his return to Germany in 1891, he obtained the highest academic degree, the Habilitation, working under the direction of Adolf von Baeyer in Munich on the determination of the equilibr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friedrich Konrad Beilstein
Friedrich Konrad Beilstein (russian: Фёдор Фёдорович Бейльштейн) (17 February 183818 October 1906), was a Russian chemist and founder of the famous ''Handbuch der organischen Chemie'' (''Handbook of Organic Chemistry''). The first edition of this work, published in 1881, covered 1,500 compounds in 2,200 pages. This handbook is now known as the Beilstein database. Life Beilstein was born in Saint Petersburg in a family of German descent. Although he mastered the Russian language, he was educated in a German school. At the age of 15, he left for the University of Heidelberg where he studied chemistry under the tuition of Robert Bunsen. After two years he moved to the University of Munich and became a pupil of Justus Liebig, but soon returned to Heidelberg. There he acquired an interest and preference for organic chemistry, which became his major. For his Ph.D., Beilstein joined Friedrich Wöhler at the University of Göttingen, receiving his doctorate in Febr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gerardus Johannes Mulder
Gerardus Johannes Mulder or Gerrit Jan Mulder (27 December 1802 – 18 April 1880) was a Dutch organic and analytical chemist. Life Mulder was born in Utrecht and earned a medical degree from Utrecht University. He became a reader of chemistry in Rotterdam and in 1840 he was appointed professor at Utrecht University. Protein Following a suggestion by Jöns Jacob Berzelius, Mulder used the term protein in his 1838 paper, "On the composition of some animal substances" (originally in French but translated in 1839 to German). In the same publication, he also proposed that animals draw most of their protein from plants.Bulletin des Sciences Physiques et Naturelles en Néerlande (1838). pg 104SUR LA COMPOSITION DE QUELQUES SUBSTANCES ANIMALES/ref> Mulder "was the first to propose a theory concerning the causes of the differences between albumin, casein, and fibrin, and other substances more or less similar to them in physical properties and in their chemical behavior when exposed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polysaccharide
Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with water (hydrolysis) using amylase enzymes as catalyst, which produces constituent sugars (monosaccharides, or oligosaccharides). They range in structure from linear to highly branched. Examples include storage polysaccharides such as starch, glycogen and galactogen and structural polysaccharides such as cellulose and chitin. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure, these macromolecules can have distinct properties from their monosaccharide building blocks. They may be amorphous or even insoluble in water. When all the monosaccharides in a polysaccharide are the same type, the polysaccharide is called a homopolysaccharide or homoglycan, but when more t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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