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Osmotic Shock
Osmotic shock or osmotic stress is physiologic dysfunction caused by a sudden change in the solute concentration around a cell, which causes a rapid change in the movement of water across its cell membrane. Under hypertonic conditions - conditions of high concentrations of either salts, substrates or any solute in the supernatant - water is drawn out of the cells through osmosis. This also inhibits the transport of substrates and cofactors into the cell thus “shocking” the cell. Alternatively, under hypotonic conditions - when concentrations of solutes are low - water enters the cell in large amounts, causing it to swell and either burst or undergo apoptosis. All organisms have mechanisms to respond to osmotic shock, with sensors and signal transduction networks providing information to the cell about the osmolarity of its surroundings; these signals activate responses to deal with extreme conditions. Cells that have a cell wall tend to be more resistant to osmotic shock bec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryotes
The eukaryotes ( ) constitute the domain of Eukaryota or Eukarya, organisms whose cells have a membrane-bound nucleus. All animals, plants, fungi, seaweeds, and many unicellular organisms are eukaryotes. They constitute a major group of life forms alongside the two groups of prokaryotes: the Bacteria and the Archaea. Eukaryotes represent a small minority of the number of organisms, but given their generally much larger size, their collective global biomass is much larger than that of prokaryotes. The eukaryotes emerged within the archaeal kingdom Promethearchaeati and its sole phylum Promethearchaeota. This implies that there are only two domains of life, Bacteria and Archaea, with eukaryotes incorporated among the Archaea. Eukaryotes first emerged during the Paleoproterozoic, likely as flagellated cells. The leading evolutionary theory is they were created by symbiogenesis between an anaerobic Promethearchaeati archaean and an aerobic proteobacterium, which form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choline
Choline is a cation with the chemical formula . Choline forms various Salt (chemistry), salts, such as choline chloride and choline bitartrate. An essential nutrient for animals, it is a structural component of phospholipids and cell membranes. Choline is used to synthesize acetylcholine, a neurotransmitter involved in muscle control and numerous functions of the nervous system. Choline is involved in early development of the brain, gene expression, cell membrane Signaling peptide receptor, signaling, and brain metabolism. Although humans synthesize choline in the liver, the amount produced naturally is insufficient to meet cellular functions, requiring that some choline be obtained from foods or dietary supplements. Foods rich in choline include meats, poultry, eggs, and other animal-based products, cruciferous vegetables, beans, nuts, and whole grains. Choline is present in breast milk and is commonly added as an food additive, ingredient to baby foods. Chemistry Choline i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimethylglycine
Trimethylglycine is an amino acid derivative with the formula . A colorless, water-soluble solid, it occurs in plants. Trimethylglycine is a zwitterion: the molecule contains both a quaternary ammonium cation, quaternary ammonium group and a carboxylate group. Trimethylglycine was the first betaine discovered; originally it was simply called betaine because it was discovered in sugar beets (''Beta vulgaris'' subsp. ''vulgaris''). Several other betaines are now known. Medical uses Betaine, sold under the brand name Cystadane, 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). The most common side effect is elevated levels of methionine in the blood. The EU has authorized the health claim that betaine "contributes to normal homocysteine metabolism.". Biological function Biosynthesis In most organisms, gly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Betaines
A betaine () in chemistry is any neutral chemical compound with a positively charged cationic functional group that bears no hydrogen atom, such as a quaternary ammonium or phosphonium cation (generally: onium ions), and with a negatively charged functional group, such as a carboxylate group that may not be adjacent to the cationic site. Historically, the term was reserved for trimethylglycine (TMG), which is involved in methylation reactions and detoxification of homocysteine. This is a modified amino acid consisting of glycine with three methyl groups serving as methyl donor for various metabolic pathways. Pronunciation The pronunciation of the compound reflects its origin and first isolation from sugar ''beets'' (''Beta vulgaris'' subsp. ''vulgaris''), and does not derive from the Greek letter beta (β). It is commonly pronounced ''beta-INE'' or ''BEE-tayn''. Glycine betaine The original betaine, ''N'',''N'',''N''-trimethylglycine, was named after its discovery in sug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Creatine
Creatine ( or ) is an organic compound with the nominal formula . It exists in various tautomers in solutions (among which are neutral form and various zwitterionic forms). Creatine is found in vertebrates, where it facilitates recycling of adenosine triphosphate (ATP), primarily in muscle and brain tissue. Recycling is achieved by converting adenosine diphosphate (ADP) back to ATP via donation of phosphate groups. Creatine also acts as a Buffer solution, buffer. History Creatine was first identified in 1832 when Michel Eugène Chevreul isolated it from the basified water-extract of skeletal muscle. He later named the crystallized precipitate after the Ancient Greek, Greek word for meat, ('). In 1928, creatine was shown to exist in Tautomer, equilibrium with creatinine. Studies in the 1920s showed that consumption of large amounts of creatine did not result in its excretion. This result pointed to the ability of the body to store creatine, which in turn suggested its use as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taurine-transporting ATPase
In enzymology, a taurine-transporting ATPase () is an enzyme that catalyzes the chemical reaction. :ATP + H2O + taurineout \rightleftharpoons ADP + phosphate + taurinein The 3 substrates of this enzyme are ATP, H2O, and taurine, whereas its 3 products are ADP, phosphate, and taurine. This enzyme belongs to the family of hydrolases, specifically those acting on acid anhydrides to catalyse transmembrane movement of substances. The systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature. A semisystematic name or semitrivi ... of this enzyme class is ATP phosphohydrolase (taurine-importing). References Further reading * EC 3.6.3 Enzymes of unknown structure {{3.6-enzyme-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taurine
Taurine (), or 2-aminoethanesulfonic acid, is a naturally occurring amino sulfonic acid that is widely distributed in animal tissues. It is a major constituent of bile and can be found in the large intestine. It is named after Latin (cognate to Ancient Greek , ) meaning bull or ox, as it was first isolated from ox bile in 1827 by German scientists Friedrich Tiedemann and Leopold Gmelin. It was identified in human bile in 1846 by Edmund Ronalds. Although taurine is abundant in human organs, it is not an essential human dietary nutrient and is not included among nutrients with a recommended intake level. Among the diverse pathways by which natural taurine can be biosynthesized, its human pathways (primarily in the human liver) are from cysteine and/or methionine. Taurine is commonly sold as a dietary supplement, but there is no good clinical evidence that taurine supplements provide any benefit to human health. Taurine is used as a food additive for cats (who require ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inositol
In biochemistry, medicine, and related sciences, inositol generally refers to ''myo''-inositol (formerly ''meso''-inositol), the most important stereoisomer of the chemical compound cyclohexane-1,2,3,4,5,6-hexol. Its elemental formula, formula is ; the molecule has a ring of six carbon atoms, each with a hydrogen atom and a hydroxyl group (–OH). In ''myo''-inositol, two of the hydroxyls, neither adjacent nor opposite, lie above the respective hydrogens relative to the mean plane of the ring. The compound is a carbohydrate, specifically a sugar alcohol (as distinct from aldoses like glucose) with half the sweetness of sucrose (table sugar). It is one of the most ancient components of living beings with multiple functions in eukaryotes, including structural lipids and secondary messengers. A human kidney makes about two grams per day from glucose, but other tissues synthesize it too. The highest concentration is in the brain, where it plays an important role in making other neurot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osmolyte
Osmolytes are low-molecular-weight organic compounds that influence the properties of biological fluids. Osmolytes are a class of organic molecules that play a significant role in regulating osmotic pressure and maintaining cellular homeostasis in various organisms, particularly in response to environmental stressors. 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 carrying water, restoring normal cell volume. These molecules are involved in counteracting the effects of osmotic stress, which occurs when there are fluctuations in the concentration of solutes (such as ions and sugars) inside and outside cells. Osmolytes help cells adapt to changing osmotic conditions, thereby ensuring their survival and functionality. Osmolytes also interact with the constituents of the cell, e.g., the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purinergic Receptor
Purinergic receptors, also known as purinoceptors, are a family of plasma membrane molecules that are found in almost all mammalian tissues. Within the field of purinergic signalling, these receptors have been implicated in learning and memory, locomotor and feeding behavior, and sleep. More specifically, they are involved in several cellular functions, including proliferation and migration of neural stem cells, vascular reactivity, apoptosis and cytokine secretion. These functions have not been well characterized and the effect of the extracellular microenvironment on their function is also poorly understood. Geoff Burnstock originally separated purinoceptors into P1 adenosine receptors and P2 nucleotide (ATP, ADP) receptors. P2 receptors were later subdivided into P2X, P2Y, P2T, and P2Z receptors. Subclasses X and Y mediated vasoconstriction and vasodilation, respectively, in the smooth muscle of some arteries. They had been observed in blood vessels, smooth muscle, heart, he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenothiazine
Phenothiazine, abbreviated PTZ, is an organic compound that has the formula S(C6H4)2NH and is related to the thiazine-class of heterocyclic compounds. Derivatives of phenothiazine are highly bioactive and have widespread use and rich history. The derivatives chlorpromazine and promethazine revolutionized the fields of psychiatry and allergy treatment, respectively. An earlier derivative, methylene blue, was one of the first antimalarial drugs, and derivatives of phenothiazine are currently under investigation as possible anti-infective drugs. Phenothiazine is a prototypical pharmaceutical lead structure in medicinal chemistry. Uses Phenothiazine itself is only of theoretical interest, but derivatives of it revolutionized psychiatry, other fields of medicine, and pest management. Other derivatives have been studied for possible use in advanced batteries and fuel cells. Phenothiazine-derived drugs In 1876, methylene blue, a derivative of phenothiazine, was synthesized by H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
