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Glucopyranose
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. Glucos ...
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Carbohydrate
In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or may not be different from ''n''), which does not mean the H has covalent bonds with O (for example with , H has a covalent bond with C but not with O). However, not all carbohydrates conform to this precise stoichiometric definition (e.g., uronic acids, deoxy-sugars such as fucose), nor are all chemicals that do conform to this definition automatically classified as carbohydrates (e.g. formaldehyde and acetic acid). The term is most common in biochemistry, where it is a synonym of saccharide (), a group that includes sugars, starch, and cellulose. The saccharides are divided into four chemical groups: monosaccharides, disaccharides, oligosaccharides, and polysaccharides. Monosaccharides and disaccharides, the smallest (lower molecular weight ...
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Haworth Projection
In chemistry, a Haworth projection is a common way of writing a structural formula to represent the cyclic structure of monosaccharides with a simple three-dimensional perspective. Haworth projection approximate the shapes of the actual molecules better for furanoses -which are in reality nearly planar- than for pyranoses which exist in solution in the chair conformation. Organic chemistry and especially biochemistry are the areas of chemistry that use the Haworth projection the most. The Haworth projection was named after the British chemist Sir Norman Haworth. A Haworth projection has the following characteristics: * Carbon is the implicit type of atom. In the example on the right, the atoms numbered from 1 to 6 are all carbon atoms. Carbon 1 is known as the anomeric carbon. * Hydrogen atoms on carbon are implicit. In the example, atoms 1 to 6 have extra hydrogen atoms not depicted. * A thicker line indicates atoms that are closer to the observer. In the example on the righ ...
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Monosaccharide
Monosaccharides (from Greek '' monos'': single, '' sacchar'': sugar), also called simple sugars, are the simplest forms of sugar and the most basic units (monomers) from which all carbohydrates are built. They are usually colorless, water-soluble, and crystalline solids. Contrary to their name (sugars), only some monosaccharides have a sweet taste. Most monosaccharides have the formula (though not all molecules with this formula are monosaccharides). Examples of monosaccharides include glucose (dextrose), fructose (levulose), and galactose. Monosaccharides are the building blocks of disaccharides (such as sucrose and lactose) and polysaccharides (such as cellulose and starch). The table sugar used in everyday vernacular is itself a disaccharide sucrose comprising one molecule of each of the two monosaccharides D-glucose and D-fructose. Each carbon atom that supports a hydroxyl group is chiral, except those at the end of the chain. This gives rise to a number of isomeric ...
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Aldehyde
In organic chemistry, an aldehyde () is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl group. Aldehydes are common and play important roles in the technology and biological spheres. Structure and bonding Aldehydes feature a carbon center that is connected by a double bond to oxygen and a single bond to hydrogen and single bond to a third substituent, which is carbon or, in the case of formaldehyde, hydrogen. The central carbon is often described as being sp2- hybridized. The aldehyde group is somewhat polar. The C=O bond length is about 120-122 picometers. Physical properties and characterization Aldehydes have properties that are diverse and that depend on the remainder of the molecule. Smaller aldehydes are more soluble in water, formaldehyde and acetaldehyde completely so. The volatile aldehydes have pungent odors. Aldeh ...
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Jean Baptiste Dumas
Jean Baptiste André Dumas (14 July 180010 April 1884) was a French chemist, best known for his works on organic analysis and synthesis, as well as the determination of atomic weights (relative atomic masses) and molecular weights by measuring vapor densities. He also developed a method for the analysis of nitrogen in compounds. Biography Dumas was born in Alès (Gard), and became an apprentice to an apothecary in his native town. In 1816, he moved to Geneva, where he attended lectures by M. A. Pictet in physics, C. G. de la Rive in chemistry, and A. P. de Candolle in botany, and before he had reached his majority, he was engaged with Pierre Prévost in original work on problems of physiological chemistry and embryology. In 1822, he moved to Paris, acting on the advice of Alexander von Humboldt, where he became professor of chemistry, initially at the Lyceum, later (1835) at the École polytechnique. He was one of the founders of the École centrale des arts et manufactur ...
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Sucrose
Sucrose, a disaccharide, is a sugar composed of glucose and fructose subunits. It is produced naturally in plants and is the main constituent of white sugar. It has the molecular formula . For human consumption, sucrose is extracted and refined from either sugarcane or sugar beet. Sugar mills – typically located in tropical regions near where sugarcane is grown – crush the cane and produce raw sugar which is shipped to other factories for refining into pure sucrose. Sugar beet factories are located in temperate climates where the beet is grown, and process the beets directly into refined sugar. The sugar-refining process involves washing the raw sugar crystals before dissolving them into a sugar syrup which is filtered and then passed over carbon to remove any residual colour. The sugar syrup is then concentrated by boiling under a vacuum and crystallized as the final purification process to produce crystals of pure sucrose that are clear, odorless, and sweet. Sugar ...
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Johann Tobias Lowitz
Johann Tobias Lowitz (russian: Товий Егорович Ловиц 25 April 1757 – 7 December 1804) was a German-Russian chemist and pharmacist. He was among the first to notice the clarification of liquids by the use of charcoal for adsorption and applied it for a range of applications. Biography Lowitz was born in Göttingen to the mathematician and cartographer Georg Moritz (1722–74) and Dorothea née Riepenhausen (1723–65). In 1767 he moved to St Petersburg along with his father and joined the expedition to the Caspian region during which he and his father were captured by a band of rebels who hanged his father. Lowitz escaped and after returning, studied at the St. Petersburg Gymnasium and became an assistant at the court pharmacy. He went to Göttingen to study pharmacy from 1780 and from 1783 he began to make a journey on foot to St. Petersburg and returned to work at the court pharmacy in 1784. He conducted experiments in chemistry and in 1785 he developed meth ...
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Andreas Sigismund Marggraf
Andreas Sigismund Marggraf (; 3 March 1709 – 7 August 1782) was a German chemist from Berlin, then capital of the Margraviate of Brandenburg, and a pioneer of analytical chemistry. He isolated zinc in 1746 by heating calamine and carbon. Though he was not the first to do so, Marggraf is credited with carefully describing the process and establishing its basic theory. In 1747, Marggraf announced his discovery of sugar in beets and devised a method using alcohol to extract it. His student Franz Achard later devised an economical industrial method to extract the sugar in its pure form. Life Andreas Sigismund Marggraf was the son of the pharmacist Henning Christian Marggraf (1680–1754), who owned a pharmacy in Berlin and lectured at the Collegium Medico-Chirurgicum (medical/surgical school). Andreas came in contact with the pharmaceutical and medical business early and started studying at the medical school in 1725. He studied with Caspar Neumann in Berlin, Germany but he also ...
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Raisin
A raisin is a dried grape. Raisins are produced in many regions of the world and may be eaten raw or used in cooking, baking, and brewing. In the United Kingdom, Ireland, New Zealand, and Australia, the word ''raisin'' is reserved for the dark-colored dried large grape, with '' sultana'' being a golden-colored dried grape, and '' currant'' being a dried small Black Corinth seedless grape. Etymology The word "raisin" dates back to Middle English and is a loanword from Old French; in modern French, ''raisin'' means "grape", while a dried grape is a ''raisin sec'', or "dry grape". The Old French word, in turn, developed from the Latin word '' racemus'', "a bunch of grapes". Varieties Raisin varieties depend on the type of grape and appear in a variety of sizes and colors including green, black, brown, purple, blue, and yellow. Seedless varieties include the sultana (the common American type is known as Thompson Seedless in the United States), the Zante currants (black Cor ...
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-ose
The suffix -ose ( or ) is used in biochemistry to form the names of sugars. This Latin suffix means "full of", "abounding in", "given to", or "like". Numerous systems exist to name specific sugars more descriptively. Monosaccharides, the simplest sugars, may be named according to the number of carbon atoms in each molecule of the sugar: pentose is a five-carbon monosaccharide, and hexose is a six-carbon monosaccharide. Aldehyde monosaccharides may be called aldoses; ketone monosaccharides may be called ketoses. Larger sugars such as disaccharides and polysaccharides can be named to reflect their qualities. Lactose, a disaccharide found in milk, gets its name from the Latin word for milk combined with the sugar suffix; its name means "milk sugar". The polysaccharide that makes up plant starch is named amylose, or "starch sugar"; see amyl. There are these theories about the origin of the ''-ose'' suffix:- # Derived from glucose, an important hexose whose name came from ...
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Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic period (), and the Classical period (). Ancient Greek was the language of Homer and of fifth-century Athenian historians, playwrights, and philosophers. It has contributed many words to English vocabulary and has been a standard subject of study in educational institutions of the Western world since the Renaissance. This article primarily contains information about the Epic and Classical periods of the language. From the Hellenistic period (), Ancient Greek was followed by Koine Greek, which is regarded as a separate historical stage, although its earliest form closely resembles Attic Greek and its latest form approaches Medieval Greek. There were several regional dialects of Ancient Greek, of which Attic Greek developed into Koine ...
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