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Glutamate Synthase (NADH)
In enzymology, a glutamate synthase (NADH) () is an enzyme that catalyzes the chemical reaction :2 L-glutamate + NAD+ \rightleftharpoons L-glutamine + 2-oxoglutarate + NADH + H+ Glutamate synthase facilitates the ammonium assimilation pathway, which follows the enzymes, nitrite reductase and glutamine synthase. An ammonium produced by the nitrite reductase reaction will be incorporated into carbon skeleton backbone by glutamine synthase. Glutamine will be produced because of the introduction of ammonium in the carbon backbone, which can be converted into glutamate by glutamate synthase of another pathway. These processes are common in plant roots due to the fact that if the nitrogen deficient conditions exist (with access to ammonium and nitrate ions), there will be a first priority of ammonium uptake. Thus, the two substrates of this enzyme are L-glutamate and NAD+, whereas its 4 products are L-glutamine, 2-oxoglutarate, NADH, and H+. This enzyme belongs to the family of ox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzymology
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] |
Glutamate Metabolism
Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can synthesize enough for its use. It is also the most abundant excitatory neurotransmitter in the vertebrate nervous system. It serves as the precursor for the synthesis of the inhibitory gamma-aminobutyric acid (GABA) in GABA-ergic neurons. Its molecular formula is . Glutamic acid exists in three optically isomeric forms; the dextrorotatory -form is usually obtained by hydrolysis of gluten or from the waste waters of beet-sugar manufacture or by fermentation.Webster's Third New International Dictionary of the English Language Unabridged, Third Edition, 1971. Its molecular structure could be idealized as HOOC−CH()−()2−COOH, with two carboxyl groups −COOH and one amino group −. However, in the solid state and mildly acidic water solutio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glutamate Synthase (NADPH)
In enzymology, a glutamate synthase (NADPH) () is an enzyme that catalyzes the chemical reaction :L-glutamine + 2-oxoglutarate + NADPH + H+ \rightleftharpoons 2 L-glutamate + NADP+ Thus, the four substrates of this enzyme are L-glutamine, 2-oxoglutarate (α-ketoglutarate), NADPH, and H+, whereas the two products are L-glutamate and NADP+. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH2 group of donors with NAD+ or NADP+ as acceptor. This enzyme participates in glutamate metabolism and nitrogen metabolism. It has 5 cofactors: FAD, Iron, FMN, Sulfur, and Iron-sulfur. It occurs in bacteria and plants but not animals, and is important as it provides glutamate for the glutamine synthetase reaction. Nomenclature 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 pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glutamate Synthase (ferredoxin)
In enzymology, a glutamate synthase (ferredoxin) () is an enzyme that catalyzes the chemical reaction :2 L-glutamate + 2 oxidized ferredoxin \rightleftharpoons L-glutamine + 2-oxoglutarate + 2 reduced ferredoxin + 2 H+ Thus, the two substrates of this enzyme are L-glutamate and oxidized ferredoxin, whereas its 4 products are L-glutamine, 2-oxoglutarate, reduced ferredoxin, and H+. Classification This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH2 group of donors with an iron-sulfur protein as acceptor. Nomenclature The systematic name of this enzyme class is L-glutamate:ferredoxin oxidoreductase (transaminating). Other names in common use include: * ferredoxin-dependent glutamate synthase, * ferredoxin-glutamate synthase, * glutamate synthase (ferredoxin-dependent), and * ferredoxin-glutamine oxoglutarate aminotransferase (Fd-GOGAT). Biological role This enzyme participates in nitrogen metabolism. It has 5 cofactors: FAD, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glutamine Oxoglutarate Aminotransferase
Glutamate synthase (also known as Glutamine oxoglutarate aminotransferase) is an enzyme and frequently abbreviated as GOGAT. This enzyme manufactures glutamate from glutamine and α-ketoglutarate, and thus along with glutamine synthetase (abbreviated GS) plays a central role in the regulation of nitrogen assimilation in photosynthetic eukaryotes and prokaryotes."Phylogenetic Relationships Among Glutamate Synthase (GOGAT) Enzymes" Eva Zadykowicz and Deborah L. Robertson; Department of Biology, Clark University, Worcester, MA"Practical Streptomyces Genetics" Keiser et al; John Innes Foundation, Norwich, England This is of great importance as primary productivity in many marine environments is regulated by the availability of inorganic nitrogen. The primary sources of inorganic nitrogen used by marine algae are nitrate and ammonium. Both forms are ultimately incorporated into amino acids through the sequential reaction of glutamine synthetase (GS) and glutamate synthase (glutamine: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Enzymes
This article lists enzymes by their classification in the International Union of Biochemistry and Molecular Biology's Enzyme Commission (EC) numbering system. * List of EC numbers (EC 5) * List of EC numbers (EC 6) :Oxidoreductases (EC 1) (Oxidoreductase) *Dehydrogenase * Luciferase *DMSO reductase :EC 1.1 (act on the CH-OH group of donors) * :EC 1.1.1 (with NAD+ or NADP+ as acceptor) ** Alcohol dehydrogenase (NAD) ** Alcohol dehydrogenase (NADP) **Homoserine dehydrogenase ** Aminopropanol oxidoreductase **Diacetyl reductase **Glycerol dehydrogenase **Propanediol-phosphate dehydrogenase ** glycerol-3-phosphate dehydrogenase (NAD+) ** D-xylulose reductase **L-xylulose reductase **Lactate dehydrogenase **Malate dehydrogenase **Isocitrate dehydrogenase ** HMG-CoA reductase * :EC 1.1.2 (with a cytochrome as acceptor) * :EC 1.1.3 (with oxygen as acceptor) **Glucose oxidase **L-gulonolactone oxidase **Thiamine oxidase **Xanthine oxidase * :EC 1.1.4 (with a disul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flavin Mononucleotide
Flavin mononucleotide (FMN), or riboflavin-5′-phosphate, is a biomolecule produced from riboflavin (vitamin B2) by the enzyme riboflavin kinase and functions as the prosthetic group of various oxidoreductases, including NADH dehydrogenase, as well as cofactor in biological blue-light photo receptors. During the catalytic cycle, a reversible interconversion of the oxidized (FMN), semiquinone (FMNH•), and reduced (FMNH2) forms occurs in the various oxidoreductases. FMN is a stronger oxidizing agent than NAD and is particularly useful because it can take part in both one- and two-electron transfers. In its role as blue-light photo receptor, (oxidized) FMN stands out from the 'conventional' photo receptors as the signaling state and not an E/Z isomerization. It is the principal form in which riboflavin is found in cells and tissues. It requires more energy to produce, but is more soluble than riboflavin. In cells, FMN occurs freely circulating but also in several covalently b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cofactor (biochemistry)
A cofactor is a non-protein chemical compound or metallic ion that is required for an enzyme's role as a catalyst (a catalyst is a substance that increases the rate of a chemical reaction). Cofactors can be considered "helper molecules" that assist in biochemical transformations. The rates at which these happen are characterized in an area of study called enzyme kinetics. Cofactors typically differ from ligands in that they often derive their function by remaining bound. Cofactors can be divided into two types: inorganic ions and complex organic molecules called coenzymes. Coenzymes are mostly derived from vitamins and other organic essential nutrients in small amounts. (Note that some scientists limit the use of the term "cofactor" for inorganic substances; both types are included here.) Coenzymes are further divided into two types. The first is called a "prosthetic group", which consists of a coenzyme that is tightly (or even covalently) and permanently bound to a protein. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen Assimilation
Nitrogen assimilation is the formation of organic nitrogen compounds like amino acids from inorganic nitrogen compounds present in the environment. Organisms like plants, fungi and certain bacteria that can fix nitrogen gas (N2) depend on the ability to assimilate nitrate or ammonia for their needs. Other organisms, like animals, depend entirely on organic nitrogen from their food. Nitrogen assimilation in plants Plants absorb nitrogen from the soil in the form of nitrate (NO3−) and ammonium (NH4+). In aerobic soils where nitrification can occur, nitrate is usually the predominant form of available nitrogen that is absorbed. However this is not always the case as ammonia can predominate in grasslands and in flooded, anaerobic soils like rice paddies. Plant roots themselves can affect the abundance of various forms of nitrogen by changing the pH and secreting organic compounds or oxygen. This influences microbial activities like the inter-conversion of various nitrogen species, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidoreductase
In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule, the reductant, also called the electron donor, to another, the oxidant, also called the electron acceptor. This group of enzymes usually utilizes NADP+ or NAD+ as cofactors. Transmembrane oxidoreductases create electron transport chains in bacteria, chloroplasts and mitochondria, including respiratory complexes I, II and III. Some others can associate with biological membranes as peripheral membrane proteins or be anchored to the membranes through a single transmembrane helix. in ...
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