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Cholinesterase
The enzyme cholinesterase (EC 3.1.1.8, choline esterase; systematic name acylcholine acylhydrolase) catalyses the hydrolysis of choline-based esters: : an acylcholine + H2O = choline + a carboxylate Several of these serve as neurotransmitters. Thus, it is either of two enzymes that catalyze the hydrolysis of these cholinergic neurotransmitters, such as breaking acetylcholine into choline and acetic acid. These reactions are necessary to allow a cholinergic neuron to return to its resting state after activation. For example, in muscle contraction, acetylcholine at a neuromuscular junction triggers a contraction; but for the muscle to relax afterward, rather than remaining locked in a tense state, the acetylcholine must be broken down by a choline esterase. The main type for that purpose is acetylcholinesterase (also called choline esterase I or erythrocyte cholinesterase); it is found mainly in chemical synapses and red blood cell membranes. The other type is butyrylcholinestera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylcholinesterase
Acetylcholinesterase (HGNC symbol ACHE; EC 3.1.1.7; systematic name acetylcholine acetylhydrolase), also known as AChE, AChase or acetylhydrolase, is the primary cholinesterase in the body. It is an enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ... that catalysis, catalyzes the breakdown of acetylcholine and some other choline esters that function as neurotransmitters: : acetylcholine + H2O = choline + acetate It is found at mainly neuromuscular junctions and in chemical synapses of the cholinergic type, where its activity serves to terminate neurotransmission, synaptic transmission. It belongs to the carboxylesterase family of enzymes. It is the primary target of inhibition by organophosphorus compounds such as nerve agents and pesticides. Enzyme structure and mechani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butyrylcholinesterase
Butyrylcholinesterase (HGNC symbol BCHE; EC 3.1.1.8), also known as BChE, BuChE, BuChase, pseudocholinesterase, or plasma (cholin)esterase, is a nonspecific cholinesterase enzyme that hydrolyses many different choline-based esters. In humans, it is made in the liver, found mainly in blood plasma, and encoded by the ''BCHE'' gene. It is very similar to the neuronal acetylcholinesterase, which is also known as RBC or erythrocyte cholinesterase. The term "serum cholinesterase" is generally used in reference to a clinical test that reflects levels of both of these enzymes in the blood. Assay of butyrylcholinesterase activity in plasma can be used as a liver function test as both hypercholinesterasemia and hypocholinesterasemia indicate pathological processes. The half-life of BCHE is approximately 10 to 14 days. Butyrylcholine is a synthetic compound that does not occur in the body naturally. It is used as a tool to distinguish between acetylcholinesterase and butyrylcholinesterase. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylcholine
Acetylcholine (ACh) is an organic chemical that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Parts in the body that use or are affected by acetylcholine are referred to as cholinergic. Substances that increase or decrease the overall activity of the cholinergic system are called cholinergics and anticholinergics, respectively. Acetylcholine is the neurotransmitter used at the neuromuscular junction—in other words, it is the chemical that motor neurons of the nervous system release in order to activate muscles. This property means that drugs that affect cholinergic systems can have very dangerous effects ranging from paralysis to convulsions. Acetylcholine is also a neurotransmitter in the autonomic nervous system, both as an internal transmitter for the sympathetic nervous system and as the final product released by the parasymp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cholinergic
Cholinergic agents are compounds which mimic the action of acetylcholine and/or butyrylcholine. In general, the word "choline" describes the various quaternary ammonium salts containing the ''N'',''N'',''N''-trimethylethanolammonium cation. Found in most animal tissues, choline is a primary component of the neurotransmitter acetylcholine and functions with inositol as a basic constituent of lecithin. Choline also prevents fat deposits in the liver and facilitates the movement of fats into cells. The parasympathetic nervous system, which uses acetylcholine almost exclusively to send its messages, is said to be almost entirely cholinergic. Neuromuscular junctions, preganglionic neurons of the sympathetic nervous system, the basal forebrain, and brain stem complexes are also cholinergic, as are the receptor for the merocrine sweat glands. In neuroscience and related fields, the term cholinergic is used in these related contexts: * A substance (or ligand) is cholinergic if it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HUGO Gene Nomenclature Committee
The HUGO Gene Nomenclature Committee (HGNC) is a committee of the Human Genome Organisation (HUGO) that sets the standards for human gene nomenclature. The HGNC approves a ''unique'' and ''meaningful'' name for every known human gene, based on a query of experts. In addition to the name, which is usually 1 to 10 words long, the HGNC also assigns a symbol (a short group of characters) to every gene. As with an SI symbol, a gene symbol is like an abbreviation but is more than that, being a second unique name that can stand on its own just as much as substitute for the longer name. It may not necessarily "stand for" the initials of the name, although many gene symbols do reflect that origin. Purpose Especially gene abbreviations/symbols but also full gene names are often not specific for a single gene. A marked example is CAP which can refer to any of 6 different genes (BRD4'', CAP1'', HACD1'', LNPEP'', SERPINB6'', and SORBS1''). The HGNC short gene names, or gene symbols, unlike ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the circulatory system is also known as ''peripheral blood'', and the blood cells it carries, ''peripheral blood cells''. Blood is composed of blood cells suspended in blood plasma. Plasma, which constitutes 55% of blood fluid, is mostly water (92% by volume), and contains proteins, glucose, mineral ions, hormones, carbon dioxide (plasma being the main medium for excretory product transportation), and blood cells themselves. Albumin is the main protein in plasma, and it functions to regulate the colloidal osmotic pressure of blood. The blood cells are mainly red blood cells (also called RBCs or erythrocytes), white blood cells (also called WBCs or leukocytes) and platelets (also called thrombocytes). The most abundant cells in vertebrate blo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapse
In the nervous system, a synapse is a structure that permits a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or to the target effector cell. Synapses are essential to the transmission of nervous impulses from one neuron to another. Neurons are specialized to pass signals to individual target cells, and synapses are the means by which they do so. At a synapse, the plasma membrane of the signal-passing neuron (the ''presynaptic'' neuron) comes into close apposition with the membrane of the target (''postsynaptic'') cell. Both the presynaptic and postsynaptic sites contain extensive arrays of molecular machinery that link the two membranes together and carry out the signaling process. In many synapses, the presynaptic part is located on an axon and the postsynaptic part is located on a dendrite or soma. Astrocytes also exchange information with the synaptic neurons, responding to synaptic activity and, in turn, regulating neurotransmission. Syna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liver
The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it is located in the quadrant (anatomy), right upper quadrant of the abdomen, below the thoracic diaphragm, diaphragm. Its other roles in metabolism include the regulation of Glycogen, glycogen storage, decomposition of red blood cells, and the production of hormones. The liver is an accessory digestive organ that produces bile, an alkaline fluid containing cholesterol and bile acids, which helps the fatty acid degradation, breakdown of fat. The gallbladder, a small pouch that sits just under the liver, stores bile produced by the liver which is later moved to the small intestine to complete digestion. The liver's highly specialized biological tissue, tissue, consisting mostly of hepatocytes, regulates a w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butyl
In organic chemistry, butyl is a four-carbon alkyl radical or substituent group with general chemical formula , derived from either of the two isomers (''n''-butane and isobutane) of butane. The isomer ''n''-butane can connect in two ways, giving rise to two "-butyl" groups: * If it connects at one of the two terminal carbon atoms, it is normal butyl or ''n''-butyl: (preferred IUPAC name: butyl) * If it connects at one of the non-terminal (internal) carbon atoms, it is secondary butyl or ''sec''-butyl: (preferred IUPAC name: butan-2-yl) The second isomer of butane, isobutane, can also connect in two ways, giving rise to two additional groups: * If it connects at one of the three terminal carbons, it is isobutyl: (preferred IUPAC name: 2-methylpropyl) * If it connects at the central carbon, it is tertiary butyl, ''tert''-butyl or ''t''-butyl: (preferred IUPAC name: ''tert''-butyl) Nomenclature According to IUPAC nomenclature, "isobutyl", "''sec''-butyl", and "''tert''-b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butyric Acid
Butyric acid (; from grc, βούτῡρον, meaning "butter"), also known under the systematic name butanoic acid, is a straight-chain alkyl carboxylic acid with the chemical formula CH3CH2CH2CO2H. It is an oily, colorless liquid with an unpleasant odor. Isobutyric acid (2-methylpropanoic acid) is an isomer. Salts and esters of butyric acid are known as butyrates or butanoates. The acid does not occur widely in nature, but its esters are widespread. It is a common industrial chemical and an important component in the mammalian gut. History Butyric acid was first observed in impure form in 1814 by the French chemist Michel Eugène Chevreul. By 1818, he had purified it sufficiently to characterize it. However, Chevreul did not publish his early research on butyric acid; instead, he deposited his findings in manuscript form with the secretary of the Academy of Sciences in Paris, France. Henri Braconnot, a French chemist, was also researching the composition of butter and was publ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butyrylcholine
Butyrylcholine is a choline-based ester that can function as a neurotransmitter. It is similar to acetylcholine, with activation of some of the same receptors as acetylcholine. Butyrylcholine is a synthetic compound and does not occur in the body naturally. It is used as a clinical laboratory tool to distinguish between the cholinesterases; acetylcholinesterase and butyrylcholinesterase Butyrylcholinesterase ( HGNC symbol BCHE; EC 3.1.1.8), also known as BChE, BuChE, BuChase, pseudocholinesterase, or plasma (cholin)esterase, is a nonspecific cholinesterase enzyme that hydrolyses many different choline-based esters. In humans, it ... preferentially lyse acetylcholine and butyrylcholine, respectively. It is also known as pseudocholinesterase. References Quaternary ammonium compounds Butyrate esters {{nervous-system-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
