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Nucleotidase
A nucleotidase is a hydrolytic enzyme that catalyzes the hydrolysis of a nucleotide into a nucleoside and a phosphate. : A nucleotide + H2O = a nucleoside + phosphate For example, it converts adenosine monophosphate to adenosine, and guanosine monophosphate to guanosine. Nucleotidases have an important function in digestion in that they break down consumed nucleic acids Nucleic acids are large biomolecules that are crucial in all cells and viruses. They are composed of nucleotides, which are the monomer components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nucleic a .... They can be divided into two categories, based upon the end that is hydrolyzed: * : 5'-nucleotidase - NT5C, NT5C1A, NT5C1B, NT5C2, NT5C3 * : 3'-nucleotidase - NT3 5'-Nucleotidases cleave off the phosphate from the 5' end of the sugar moiety. They can be classified into various kinds depending on their substrate preferences and subcellular localization. Membrane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5'-nucleotidase
5′-Nucleotidase (EC 3.1.3.5) is an enzyme which catalyzes the phosphorylytic cleavage of 5′-nucleotides. Although originally found in snake venom, the activity of 5'nucleotidase has been described for bacteria and plant cells, and is widely distributed in vertebrate tissue. In mammalian cells the enzyme is predominantly located in the plasma membrane and its primary role is in the conversion of extracellular nucleotides (e.g. 5'-AMP), which are generally impermeable, to the corresponding nucleoside (e.g. adenosine) which can readily enter most cells. Consequently, the enzyme plays a key role in the metabolism of nucleotides. The enzyme has a wide substrate specificity for nucleotides and has been shown to hydrolyze 5'nucleotides rapidly, ribose-5-phosphate slowly, and other phosphate esters extremely slowly (if at all). The enzyme catalysis, catalyses the following reaction: : a 5′-nucleotide + H2O a nucleoside + phosphate The 5′-nucleotidase-catalyzed reaction of an A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleoside
Nucleosides are glycosylamines that can be thought of as nucleotides without a phosphate group. A nucleoside consists simply of a nucleobase (also termed a nitrogenous base) and a five-carbon sugar (ribose or 2'-deoxyribose) whereas a nucleotide is composed of a nucleobase, a five-carbon sugar, and one or more phosphate groups. In a nucleoside, the anomeric carbon is linked through a glycosidic bond to the N9 of a purine or the N1 of a pyrimidine. Nucleotides are the molecular building blocks of DNA and RNA. List of nucleosides and corresponding nucleobases ''This list does not include modified nucleobases and the corresponding nucleosides'' Each chemical has a short symbol, useful when the chemical family is clear from the context, and a longer symbol, if further disambiguation is needed. For example, long nucleobase sequences in genomes are usually described by CATG symbols, not Cyt-Ade-Thy-Gua (see '' Nucleic acid sequence § Notation''). Sources Nucleosides can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolase
In biochemistry, hydrolases constitute a class of enzymes that commonly function as biochemical catalysts that use water to break a chemical bond: :\ce \quad \xrightarrowtext\quad \ce This typically results in dividing a larger molecule into smaller molecules. Some common examples of hydrolase enzymes are esterases including lipases, phosphatases, glycosidases, peptidases, and nucleosidases. Esterases cleave ester bonds in lipids and phosphatases cleave phosphate groups off molecules. An example of crucial esterase is acetylcholine esterase, which assists in transforming the neuron impulse into the acetate group after the hydrolase breaks the acetylcholine into choline and acetic acid. Acetic acid is an important metabolite in the body and a critical intermediate for other reactions such as glycolysis. Lipases hydrolyze glycerides. Glycosidases cleave sugar molecules off carbohydrates and peptidases hydrolyze peptide bonds. Nucleosidases hydrolyze the bonds of nucleo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis is the cleavage of Biomolecule, biomolecules where a water molecule is consumed to effect the separation of a larger molecule into component parts. When a carbohydrate is broken into its component sugar molecules by hydrolysis (e.g., sucrose being broken down into glucose and fructose), this is recognized as saccharification. Hydrolysis reactions can be the reverse of a condensation reaction in which two molecules join into a larger one and eject a water molecule. Thus hydrolysis adds water to break down, whereas condensation builds up by removing water. Types Usually hydrolysis is a chemical process in which a molecule of water is added to a substance. Sometimes this addition causes both the su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleotide
Nucleotides are Organic compound, organic molecules composed of a nitrogenous base, a pentose sugar and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules within all Life, life-forms on Earth. Nucleotides are obtained in the diet and are also synthesized from common Nutrient, nutrients by the liver. Nucleotides are composed of three subunit molecules: a nucleobase, a pentose, five-carbon sugar (ribose or deoxyribose), and a phosphate group consisting of one to three phosphates. The four nucleobases in DNA are guanine, adenine, cytosine, and thymine; in RNA, uracil is used in place of thymine. Nucleotides also play a central role in metabolism at a fundamental, cellular level. They provide chemical energy—in the form of the nucleoside triphosphates, adenosine triphosphate (ATP), guanosine triphosphate (GTP), cytidine triphosphate (CTP), and uridine triph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphate
Phosphates are the naturally occurring form of the element phosphorus. In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid, phosphoric acid . The phosphate or orthophosphate ion is derived from phosphoric acid by the removal of three protons . Removal of one proton gives the dihydrogen phosphate ion while removal of two protons gives the hydrogen phosphate ion . These names are also used for salts of those anions, such as ammonium dihydrogen phosphate and trisodium phosphate. File:3-phosphoric-acid-3D-balls.png, Phosphoricacid File:2-dihydrogenphosphate-3D-balls.png, Dihydrogenphosphate File:1-hydrogenphosphate-3D-balls.png, Hydrogenphosphate File:0-phosphate-3D-balls.png, Phosphate or orthophosphate In organic chemistry, phosphate or orthophosphate is an organophosphate, an ester of orthophosphoric acid of the form where one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenosine Monophosphate
Adenosine monophosphate (AMP), also known as 5'-adenylic acid, is a nucleotide. AMP consists of a phosphate group, the sugar ribose, and the nucleobase adenine. It is an ester of phosphoric acid and the nucleoside adenosine. As a substituent it takes the form of the prefix adenylyl-. AMP plays an important role in many cellular metabolic processes, being interconverted to adenosine triphosphate (ATP) and adenosine diphosphate (ADP), as well as allosterically activating enzymes such as myophosphorylase-b. AMP is also a component in the synthesis of RNA. AMP is present in all known forms of life. Production and degradation AMP does not have the high energy phosphoanhydride bond associated with ADP and ATP. AMP can be produced from ADP by the myokinase (adenylate kinase) reaction when the ATP reservoir in the cell is low: : 2 ADP → ATP + AMP Or AMP may be produced by the hydrolysis of one high energy phosphate bond of ADP: : ADP + H2O → AMP + Pi AMP can also be forme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenosine
Adenosine (symbol A) is an organic compound that occurs widely in nature in the form of diverse derivatives. The molecule consists of an adenine attached to a ribose via a β-N9- glycosidic bond. Adenosine is one of the four nucleoside building blocks of RNA (and its derivative deoxyadenosine is a building block of DNA), which are essential for all life on Earth. Its derivatives include the energy carriers adenosine mono-, di-, and triphosphate, also known as AMP/ADP/ATP. Cyclic adenosine monophosphate (cAMP) is pervasive in signal transduction. Adenosine is used as an intravenous medication for some cardiac arrhythmias. Adenosyl (abbreviated Ado or 5'-dAdo) is the chemical group formed by removal of the 5′-hydroxy (OH) group. It is found in adenosylcobalamin (an active form of vitamin B12) and as a radical in the radical SAM enzymes. Medical uses Supraventricular tachycardia In individuals with supraventricular tachycardia (SVT), adenosine is a first line trea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guanosine Monophosphate
Guanosine monophosphate (GMP), also known as 5′-guanidylic acid or guanylic acid (conjugate base guanylate), is a nucleotide that is used as a monomer in RNA. It is an ester of phosphoric acid with the nucleoside guanosine. GMP consists of the phosphate group, the pentose sugar ribose, and the nucleobase guanine; hence it is a ribonucleotide monophosphate. Guanosine monophosphate is commercially produced by microbial fermentation. As an acyl substituent, it takes the form of the prefix guanylyl-. ''De novo'' synthesis GMP synthesis starts with D-ribose 5′-phosphate, a product of the pentose phosphate pathway. The synthesis proceeds by the gradual formation of the purine ring on carbon-1 of ribose, with CO2, glutamine, glycine, aspartate and one-carbon derivatives of tetrahydrofolate donating various elements towards the building of the ring. As inhibitor of guanosine monophosphate synthesis in experimental models, the glutamine analogue DON can be used.''Ahluwalia GS et al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guanosine
Guanosine (symbol G or Guo) is a purine nucleoside comprising guanine attached to a ribose ( ribofuranose) ring via a β-N9- glycosidic bond. Guanosine can be phosphorylated to become guanosine monophosphate (GMP), cyclic guanosine monophosphate (cGMP), guanosine diphosphate (GDP), and guanosine triphosphate (GTP). These forms play important roles in various biochemical processes such as synthesis of nucleic acids and proteins, photosynthesis, muscle contraction, and intracellular signal transduction (cGMP). When guanine is attached by its N9 nitrogen to the C1 carbon of a deoxyribose ring it is known as deoxyguanosine. Physical and chemical properties Guanosine is a white, crystalline powder with no odor and mild saline taste. It is very soluble in acetic acid, slightly soluble in water, insoluble in ethanol, diethyl ether, benzene and chloroform. Functions Guanosine is required for an RNA splicing reaction in mRNA, when a "self-splicing" intron removes itself from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digestion
Digestion is the breakdown of large insoluble food compounds into small water-soluble components so that they can be absorbed into the blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the blood stream. Digestion is a form of catabolism that is often divided into two processes based on how food is broken down: mechanical and chemical digestion. The term mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes. Mechanical digestion takes place in the mouth through Chewing, mastication and in the small intestine through segmentation contractions. In chemical digestion, enzymes break down food into the small compounds that the body can use. In the human digestive system, food enters the mouth and mechanical digestion of the food starts by the action of mastication (chewing), a form of mechanical digestion, and the wetting contact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleic Acids
Nucleic acids are large biomolecules that are crucial in all cells and viruses. They are composed of nucleotides, which are the monomer components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). If the sugar is ribose, the polymer is RNA; if the sugar is deoxyribose, a variant of ribose, the polymer is DNA. Nucleic acids are chemical compounds that are found in nature. They carry information in cells and make up genetic material. These acids are very common in all living things, where they create, encode, and store information in every living cell of every life-form on Earth. In turn, they send and express that information inside and outside the cell nucleus. From the inner workings of the cell to the young of a living thing, they contain and provide information via the nucleic acid sequence. This gives the RNA and DNA their unmistakable 'ladder-step' order of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
