The d- isomer, d-glucose, also known as dextrose, occurs widely in nature, but the l-isomer, l-glucose, does not. d-Glucose is one of the sixteen aldohexose stereoisomers. With six carbon atoms, it is classed as a hexose, a subcategory of the monosaccharides. Glucose has a pK value of 12.16 at 25 ☌ (77 ☏) in water. They melt at 146 ☌ (295 ☏) ( α) and 150 ☌ (302 ☏) ( β), and decompose starting at 188 ☌ (370 ☏) with release of various volatile products, ultimately leaving a residue of carbon. Glucose forms white or colorless solids that are highly soluble in water and acetic acid but poorly soluble in methanol and ethanol. In 1970, Luis Leloir was awarded the Nobel Prize in Chemistry for the discovery of glucose-derived sugar nucleotides in the biosynthesis of carbohydrates. In 1947, Bernardo Houssay (for his discovery of the role of the pituitary gland in the metabolism of glucose and the derived carbohydrates) as well as Carl and Gerty Cori (for their discovery of the conversion of glycogen from glucose) received the Nobel Prize in Physiology or Medicine. Hans von Euler-Chelpin was awarded the Nobel Prize in Chemistry along with Arthur Harden in 1929 for their "research on the fermentation of sugar and their share of enzymes in this process". Fischer nomenclature, d/ l nomenclature).įor the discovery of the metabolism of glucose Otto Meyerhof received the Nobel Prize in Physiology or Medicine in 1922. Their enantiomers were given the same name with the introduction of systematic nomenclatures, taking into account absolute stereochemistry (e.g. The names initially referred to the natural substances. Between 18, Fischer established the stereochemical configuration of all the known sugars and correctly predicted the possible isomers, applying Van 't Hoff's theory of asymmetrical carbon atoms. The synthesis of glucose established the structure of organic material and consequently formed the first definitive validation of Jacobus Henricus van 't Hoff's theories of chemical kinetics and the arrangements of chemical bonds in carbon-bearing molecules. This understanding occurred largely as a result of the investigations of Emil Fischer, a German chemist who received the 1902 Nobel Prize in Chemistry for his findings.
Since glucose is a basic necessity of many organisms, a correct understanding of its chemical makeup and structure contributed greatly to a general advancement in organic chemistry. The earlier notation according to the rotation of the plane of linearly polarized light ( d and l-nomenclature) was later abandoned in favor of the d- and l-notation, which refers to the absolute configuration of the asymmetric center farthest from the carbonyl group, and in concordance with the configuration of d- or l-glyceraldehyde. In contrast, l-fructose (a ketohexose) and l-glucose turn linearly polarized light to the left. Friedrich August Kekulé proposed the term dextrose (from the Latin dexter, meaning "right"), because in aqueous solution of glucose, the plane of linearly polarized light is turned to the right. Glucose is the term coined by Jean Baptiste Dumas in 1838, which has prevailed in the chemical literature. Glucose was discovered in grapes by another German chemist – Johann Tobias Lowitz – in 1792, and distinguished as being different from cane sugar ( sucrose). Glucose was first isolated from raisins in 1747 by the German chemist Andreas Marggraf. The suffix " -ose" is a chemical classifier, denoting a sugar. The name glucose is derived from Ancient Greek γλεῦκος ( gleûkos, "wine, must"), from γλυκύς ( glykýs, "sweet").
It is also on the list in combination with sodium chloride. Glucose, as intravenous sugar solution, is on the World Health Organization's List of Essential Medicines. In animals, glucose is released from the breakdown of glycogen in a process known as glycogenolysis.
#CHIRAL CARBON IN GLUCOSE FREE#
Glucose is naturally occurring and is found in its free state in fruits and other parts of plants. The glucose molecule can exist in an open-chain (acyclic) as well as ring (cyclic) form. Glucose is a monosaccharide containing six carbon atoms and an aldehyde group, and is therefore an aldohexose. The naturally occurring form of glucose is d-glucose, while its stereoisomer l-glucose is produced synthetically in comparatively small amounts and is less biologically active. Glucose circulates in the blood of animals as blood sugar. Glucose for metabolism is stored as a polymer, in plants mainly as starch and amylopectin, and in animals as glycogen. In energy metabolism, glucose is the most important source of energy in all organisms. 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. Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is a sugar with the molecular formula C 6 H 12 O 6.
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