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Homarine
Homarine (''N''-methyl picolinic acid betaine) is an organic compound with the chemical formula C7H7NO2. It is commonly found in aquatic organisms from phytoplankton to crustaceans, although it is not found in vertebrates. Biological function Homarine functions as an osmolyte by affecting the ionic strength of the cytosol and thereby maintaining osmotic pressure within the cell. Homarine may also act as a methyl group donor in the biosynthesis of various other ''N''-methylated chemicals, such as glycine betaine and choline. The process of methyl donation converts homarine into picolinic acid and is reversible. Etymology The name of this chemical comes from the initial discovery of the molecule in 1933 in lobster Lobsters are a family (biology), family (Nephropidae, Synonym (taxonomy), synonym Homaridae) of marine crustaceans. They have long bodies with muscular tails and live in crevices or burrows on the sea floor. Three of their five pairs of legs ... tissue: the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homarine
Homarine (''N''-methyl picolinic acid betaine) is an organic compound with the chemical formula C7H7NO2. It is commonly found in aquatic organisms from phytoplankton to crustaceans, although it is not found in vertebrates. Biological function Homarine functions as an osmolyte by affecting the ionic strength of the cytosol and thereby maintaining osmotic pressure within the cell. Homarine may also act as a methyl group donor in the biosynthesis of various other ''N''-methylated chemicals, such as glycine betaine and choline. The process of methyl donation converts homarine into picolinic acid and is reversible. Etymology The name of this chemical comes from the initial discovery of the molecule in 1933 in lobster Lobsters are a family (biology), family (Nephropidae, Synonym (taxonomy), synonym Homaridae) of marine crustaceans. They have long bodies with muscular tails and live in crevices or burrows on the sea floor. Three of their five pairs of legs ... tissue: the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, hydrogen cyanide), are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive. Although organic compounds make up only a small percentage of Earth's crust, they are of central importance because all known life is based on organic compounds. Living t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytoplankton
Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater ecosystems. The name comes from the Greek words (), meaning 'plant', and (), meaning 'wanderer' or 'drifter'. Phytoplankton obtain their energy through photosynthesis, as do trees and other plants on land. This means phytoplankton must have light from the sun, so they live in the well-lit surface layers (euphotic zone) of oceans and lakes. In comparison with terrestrial plants, phytoplankton are distributed over a larger surface area, are exposed to less seasonal variation and have markedly faster turnover rates than trees (days versus decades). As a result, phytoplankton respond rapidly on a global scale to climate variations. Phytoplankton form the base of marine and freshwater food webs and are key players in the global carbon cycle. They account for about half of global photosynthetic activity and at least half of the oxygen production, despite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustaceans
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the hexapods emerged deep in the Crustacean group, with the completed group referred to as Pancrustacea. Some crustaceans (Remipedia, Cephalocarida, Branchiopoda) are more closely related to insects and the other hexapods than they are to certain other crustaceans. The 67,000 described species range in size from '' Stygotantulus stocki'' at , to the Japanese spider crab with a leg span of up to and a mass of . Like other arthropods, crustaceans have an exoskeleton, which they moult to grow. They are distinguished from other groups of arthropods, such as insects, myriapods and chelicerates, by the possession of biramous (two-parted) limbs, and by th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osmolyte
Osmolytes are low-molecular weight organic compounds that influence the properties of biological fluids. Their primary role is to maintain the integrity of cells by affecting the viscosity, melting point, and ionic strength of the aqueous solution. When a cell swells due to external osmotic pressure, membrane channels open and allow efflux of osmolytes which carry water with them, restoring normal cell volume. Osmolytes also interact with the constituents of the cell, e.g. they influence protein folding. Common osmolytes include amino acids, sugars and polyols, methylamines, methylsulfonium compounds, and urea. Case studies Natural osmolytes that can act as osmoprotectants include trimethylamine ''N''-oxide (TMAO), dimethylsulfoniopropionate, sarcosine, betaine, glycerophosphorylcholine, myo-inositol, taurine, glycine, and others. Remarkably, TMAO has the capacity to restore glucocorticoid binding to mutant receptors. Bacteria accumulate osmolytes for protection against a high o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl Group
In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in many organic compounds. It is a very stable group in most molecules. While the methyl group is usually part of a larger molecule, bounded to the rest of the molecule by a single covalent bond (), it can be found on its own in any of three forms: methanide anion (), methylium cation () or methyl radical (). The anion has eight valence electrons, the radical seven and the cation six. All three forms are highly reactive and rarely observed. Methyl cation, anion, and radical Methyl cation The methylium cation () exists in the gas phase, but is otherwise not encountered. Some compounds are considered to be sources of the cation, and this simplification is used pervasively in organic chemistry. For example, protonation of methanol gives an elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biosynthesis
Biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. This process often consists of metabolic pathways. Some of these biosynthetic pathways are located within a single cellular organelle, while others involve enzymes that are located within multiple cellular organelles. Examples of these biosynthetic pathways include the production of lipid membrane components and nucleotides. Biosynthesis is usually synonymous with anabolism. The prerequisite elements for biosynthesis include: precursor compounds, chemical energy (e.g. ATP), and catalytic enzymes which may require coenzymes (e.g.NADH, NADPH). These elements create monomers, the building blocks for macromolecules. Some important biological macromolecules include: proteins, which are composed of amino acid monomers joined via peptide bon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycine Betaine
Trimethylglycine is an amino acid derivative that occurs in plants. Trimethylglycine was the first betaine discovered; originally it was simply called betaine because, in the 19th century, it was discovered in sugar beets. It has a sweet and umami taste. Since then, many other betaines have been discovered, and the more specific name ''glycine betaine'' distinguishes this one. Medical uses Betaine is indicated for the adjunctive treatment of homocystinuria, involving deficiencies or defects in cystathionine beta-synthase (CBS), 5,10-methylene-tetrahydrofolate reductase (MTHFR), or cobalamin cofactor metabolism (cbl). Structure and reactions Trimethylglycine is an ''N''-methylated amino acid. It is a zwitterion as the molecule contains both a quaternary ammonium cation, quaternary ammonium group and a carboxyl group. The carboxyl group will be partially protonated in aqueous solution below pH 4, that is, approximately below pH equal to (p''K''a + 2). : (aq) + (aq) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choline
Choline is an essential nutrient for humans and many other animals. Choline occurs as a cation that forms various salts (X− in the depicted formula is an undefined counteranion). Humans are capable of some ''de novo synthesis'' of choline but require additional choline in the diet to maintain health. Dietary requirements can be met by choline per se or in the form of choline phospholipids, such as phosphatidylcholine. Choline is not formally classified as a vitamin despite being an essential nutrient with an amino acid–like structure and metabolism. In most animals, choline phospholipids are necessary components in cell membranes, in the membranes of cell organelles, and in very low-density lipoproteins. Choline is required to produce acetylcholine – a neurotransmitter – and ''S''-adenosylmethionine (SAM), a universal methyl donor. Upon methylation SAM is transformed into homocysteine. Symptomatic choline deficiency causes non-alcoholic fatty liver disease and muscle dama ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picolinic Acid
Picolinic acid is an organic compound with the formula C5H4N(CO2H). It is a derivative of pyridine with a carboxylic acid (COOH) substituent at the 2-position. It is an isomer of nicotinic acid and isonicotinic acid, which have the carboxyl side chain at the 3- and 4-position, respectively. It is a white solid that is soluble in water. In synthetic organic chemistry, has been used as a substrate in the Mitsunobu reaction and in the Hammick reaction. Coordination chemistry Picolinic acid is a bidentate chelating agent of elements such as chromium, zinc, manganese, copper, iron, and molybdenum in the human body. Many of its complexes are charge-neutral and thus lipophilic. After its role in absorption was discovered, zinc picolinate dietary supplements became popular as they were shown to be an effective means of introducing zinc into the body. Production Picolinic acid is formed from 2-methylpyridine by oxidation, e.g. by means of potassium permanganate (KMnO4). : Biosynthesi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lobster
Lobsters are a family (biology), family (Nephropidae, Synonym (taxonomy), synonym Homaridae) of marine crustaceans. They have long bodies with muscular tails and live in crevices or burrows on the sea floor. Three of their five pairs of legs have claws, including the first pair, which are usually much larger than the others. Highly prized as seafood, lobsters are economically important and are often one of the most profitable commodities in coastal areas they populate. Commercially important species include two species of ''Homarus'' from the northern Atlantic Ocean and scampi (which look more like a shrimp, or a "mini lobster")—the Northern Hemisphere genus ''Nephrops'' and the Southern Hemisphere genus ''Metanephrops''. Distinction Although several other groups of crustaceans have the word "lobster" in their names, the unqualified term "lobster" generally refers to the clawed lobsters of the family Nephropidae. Clawed lobsters are not closely related to spiny lobsters o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homarus
''Homarus'' is a genus of lobsters, which include the common and commercially significant species ''Homarus americanus'' (the American lobster) and ''Homarus gammarus'' (the European lobster). The Cape lobster, which was formerly in this genus as ''H. capensis'', was moved in 1995 to the new genus ''Homarinus''. Description ''Homarus'' is one of three extant genera of clawed lobsters to show dimorphism between claws – a specialisation into a crushing claw and a cutting claw. The other similar genera are '' Nephrops'', which is much more slender, and has grooves along the claws and the abdomen, and ''Homarinus'', the Cape lobster from South Africa, which is even smaller, and has hairy claws. tp://ftp.fao.org/docrep/fao/009/t0411e/t0411e09.pdf Subfamily Nephropinae Dana, 1852 pp. 51–86 in Holthuis (1991). While analyses of morphology suggest a close relationship between ''Homarinus'' and ''Homarus'', molecular analyses using mitochondrial DNA reveal that they are not sister ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
