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Sulfolipid
Sulfolipids are a class of lipids which possess a sulfur-containing functional group. An abundant sulfolipid is sulfoquinovosyl diacylglycerol, which is composed of a glycoside of sulfoquinovose and diacylglycerol. In plants, sulfoquinovosyl diacylglycerides (SQDG) are important members of the sulfur cycle. Other important sulfolipids include sulfatide and seminolipid, each of which are sulfated glycolipids. Sulfolipids have been implicated in the functions of two of the core components of the photosynthetic electron transport chain and while not necessarily essential, might have a protective function when the photosynthetic apparatus is under stress. Must see * Sulfatide * Galactolipid Galactolipids are a type of glycolipid whose sugar group is galactose. They differ from glycosphingolipids in that they do not have nitrogen in their composition. They are the main part of plant membrane lipids where they substitute phospholipids ... *Phospholipid *Glycolipid References L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SQDG Chemical Structure
Sulfoquinovosyl diacylglycerols, abbreviated SQDG, are a class of sulfur-containing but phosphorus-free lipids (sulfolipids) found in many photosynthetic organisms. Discovery, structure and chemical properties In 1959 A. A. Benson and coworkers discovered a new sulfur-containing lipid in plants and identified it as sulfoquinovosyl diacylglycerol (SQDG). The sulfolipid structure was defined as 1,2-di-''O''-acyl-3-O-(6-deoxy-6-sulfo-α-D-glucopyranosyl)-''sn''-glycerol (SQDG). The distinctive feature of this substance is carbon bonded directly to sulfur as C-SO3. Sulfonic acids of this type are chemically stable and strong acids. Biological occurrence and functions SQDGs have been found in all photosynthetic plants, algae, cyanobacteria, purple sulfur and non-sulfur bacteria and is localised in the thylakoid membranes, being the most saturated glycolipid. SQDGs have been found to be closely associated with certain membrane proteins. In some cases the (electrostatic) interactio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfoquinovosyl Diacylglycerol
Sulfoquinovosyl diacylglycerols, abbreviated SQDG, are a class of sulfur-containing but phosphorus-free lipids ( sulfolipids) found in many photosynthetic organisms. Discovery, structure and chemical properties In 1959 A. A. Benson and coworkers discovered a new sulfur-containing lipid in plants and identified it as sulfoquinovosyl diacylglycerol (SQDG). The sulfolipid structure was defined as 1,2-di-''O''-acyl-3-O-(6-deoxy-6-sulfo-α-D-glucopyranosyl)-''sn''-glycerol (SQDG). The distinctive feature of this substance is carbon bonded directly to sulfur as C-SO3. Sulfonic acids of this type are chemically stable and strong acids. Biological occurrence and functions SQDGs have been found in all photosynthetic plants, algae, cyanobacteria, purple sulfur and non-sulfur bacteria and is localised in the thylakoid membranes, being the most saturated glycolipid. SQDGs have been found to be closely associated with certain membrane proteins. In some cases the (electrostatic) interacti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfoquinovose
Sulfoquinovose, also known as 6-sulfoquinovose and 6-deoxy-6-sulfo-D-glucopyranose, is a monosaccharide sugar that is found as a building block in the sulfolipid sulfoquinovosyl diacylglycerol (SQDG). Sulfoquinovose is a sulfonic acid derivative of glucose, the sulfonic acid group is introduced into the sugar by the enzyme UDP-sulfoquinovose synthase UDP-sulfoquinovose synthase () is an enzyme that catalyzes the chemical reaction :UDP-glucose + sulfite \rightleftharpoons UDP-6-sulfoquinovose + H2O Thus, the two substrates of this enzyme are UDP-glucose and sulfite, whereas its two products ... (SQD1). Sulfoquinovose is degraded through a metabolic process termed sulfoglycolysis. The half-life for mutarotation of sulfoquinovose at pD 7.5 and 26C is 299 minutes. See also * Sulfolipid * Sulfoglycolysis References {{Reflist Sulfonic acids Deoxy sugars Monosaccharides Sulfate esters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipid
Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include storing energy, signaling, and acting as structural components of cell membranes. Lipids have applications in the cosmetic and food industries, and in nanotechnology. Lipids may be broadly defined as hydrophobic or amphiphilic small molecules; the amphiphilic nature of some lipids allows them to form structures such as vesicles, multilamellar/unilamellar liposomes, or membranes in an aqueous environment. Biological lipids originate entirely or in part from two distinct types of biochemical subunits or "building-blocks": ketoacyl and isoprene groups. Using this approach, lipids may be divided into eight categories: fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, saccharolipids, and polyketides (derived from condensati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur
Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula S8. Elemental sulfur is a bright yellow, crystalline solid at room temperature. Sulfur is the tenth most abundant element by mass in the universe and the fifth most on Earth. Though sometimes found in pure, native form, sulfur on Earth usually occurs as sulfide and sulfate minerals. Being abundant in native form, sulfur was known in ancient times, being mentioned for its uses in ancient India, ancient Greece, China, and ancient Egypt. Historically and in literature sulfur is also called brimstone, which means "burning stone". Today, almost all elemental sulfur is produced as a byproduct of removing sulfur-containing contaminants from natural gas and petroleum.. Downloahere The greatest commercial use of the element is the production o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functional Group
In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the rest of the molecule's composition. This enables systematic prediction of chemical reactions and behavior of chemical compounds and the design of chemical synthesis. The reactivity of a functional group can be modified by other functional groups nearby. Functional group interconversion can be used in retrosynthetic analysis to plan organic synthesis. A functional group is a group of atoms in a molecule with distinctive chemical properties, regardless of the other atoms in the molecule. The atoms in a functional group are linked to each other and to the rest of the molecule by covalent bonds. For repeating units of polymers, functional groups attach to their nonpolar core of carbon atoms and thus add chemical character to carbon chains. Fun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur Cycle
The sulfur cycle is a biogeochemical cycle in which the sulfur moves between rocks, waterways and living systems. It is important in geology as it affects many minerals and in life because sulfur is an essential element ( CHNOPS), being a constituent of many proteins and cofactors, and sulfur compounds can be used as oxidants or reductants in microbial respiration. The global sulfur cycle involves the transformations of sulfur species through different oxidation states, which play an important role in both geological and biological processes. Steps of the sulfur cycle are: * Mineralization of organic sulfur into inorganic forms, such as hydrogen sulfide (H2S), elemental sulfur, as well as sulfide minerals. * Oxidation of hydrogen sulfide, sulfide, and elemental sulfur (S) to sulfate (). * Reduction of sulfate to sulfide. * Incorporation of sulfide into organic compounds (including metal-containing derivatives). These are often termed as follows: :''Assimilative sulfate reducti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfatide
Sulfatide, also known as 3-O-sulfogalactosylceramide, SM4, or sulfated galactocerebroside, is a class of sulfolipids, specifically a class of sulfoglycolipids, which are glycolipids that contain a sulfate group. Sulfatide is synthesized primarily starting in the endoplasmic reticulum and ending in the Golgi apparatus where ceramide is converted to galactocerebroside and later sulfated to make sulfatide. Of all of the galactolipids that are found in the myelin sheath, one fifth of them are sulfatide. Sulfatide is primarily found on the extracellular leaflet of the myelin plasma membrane produced by the oligodendrocytes in the central nervous system and in the Schwann cells in the peripheral nervous system. However, sulfatide is also present on the extracellular leaflet of the plasma membrane of many cells in eukaryotic organisms. Since sulfatide is a multifunctional molecule, it can be used in multiple biological areas. Aside from being a membrane component, sulfatide functions in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfatide
Sulfatide, also known as 3-O-sulfogalactosylceramide, SM4, or sulfated galactocerebroside, is a class of sulfolipids, specifically a class of sulfoglycolipids, which are glycolipids that contain a sulfate group. Sulfatide is synthesized primarily starting in the endoplasmic reticulum and ending in the Golgi apparatus where ceramide is converted to galactocerebroside and later sulfated to make sulfatide. Of all of the galactolipids that are found in the myelin sheath, one fifth of them are sulfatide. Sulfatide is primarily found on the extracellular leaflet of the myelin plasma membrane produced by the oligodendrocytes in the central nervous system and in the Schwann cells in the peripheral nervous system. However, sulfatide is also present on the extracellular leaflet of the plasma membrane of many cells in eukaryotic organisms. Since sulfatide is a multifunctional molecule, it can be used in multiple biological areas. Aside from being a membrane component, sulfatide functions in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galactolipid
Galactolipids are a type of glycolipid whose sugar group is galactose. They differ from glycosphingolipids in that they do not have nitrogen in their composition. They are the main part of plant membrane lipids where they substitute phospholipids to conserve phosphate for other essential processes. These chloroplast membranes contain a high quantity of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG). They probably also assume a direct role in photosynthesis, as they have been found in the X-ray structures of photosynthetic complexes. Galactolipids are more bioavailable than free fatty acids, and have been shown to exhibit COX mediated anti-inflammatory activity. Bio-guided fractionation of spinach leaves (''Spinacia oleracea'') revealed alpha-linolenic acid galactolipids (18:3, n-3) were responsible for inhibitory effects on tumor promoter-induced Epstein-Barr virus (EBV) activation. Recently, it has been demonstrated that this same galactolipid, 1,2-di-O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipids
Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include storing energy, signaling, and acting as structural components of cell membranes. Lipids have applications in the cosmetic and food industries, and in nanotechnology. Lipids may be broadly defined as hydrophobic or amphiphilic small molecules; the amphiphilic nature of some lipids allows them to form structures such as vesicles, multilamellar/unilamellar liposomes, or membranes in an aqueous environment. Biological lipids originate entirely or in part from two distinct types of biochemical subunits or "building-blocks": ketoacyl and isoprene groups. Using this approach, lipids may be divided into eight categories: fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, saccharolipids, and polyketides (derived from condensati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
