|
Glutamate Synthetase
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:2-o ... [...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] |
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] |
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] |
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] |
Archaea
Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebacteria kingdom), but this term has fallen out of use. Archaeal cells have unique properties separating them from the other two domains, Bacteria and Eukaryota. Archaea are further divided into multiple recognized phyla. Classification is difficult because most have not been isolated in a laboratory and have been detected only by their gene sequences in environmental samples. Archaea and bacteria are generally similar in size and shape, although a few archaea have very different shapes, such as the flat, square cells of ''Haloquadratum walsbyi''. Despite this morphological similarity to bacteria, archaea possess genes and several metabolic pathways that are more closely related to those of eukaryotes, notably for the enzymes involved ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhodophytes
Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority of species (6,793) are found in the Florideophyceae (class), and mostly consist of multicellular, marine algae, including many notable seaweeds. Red algae are abundant in marine habitats but relatively rare in freshwaters. Approximately 5% of red algae species occur in freshwater environments, with greater concentrations found in warmer areas. Except for two coastal cave dwelling species in the asexual class Cyanidiophyceae, there are no terrestrial species, which may be due to an evolutionary bottleneck in which the last common ancestor lost about 25% of its core genes and much of its evolutionary plasticity. The red algae form a distinct group characterized by having eukaryotic cells without flagella and centrioles, chloroplasts that la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanobacteria
Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blue-green algae, although they are not usually scientifically classified as algae. They appear to have originated in a freshwater or terrestrial environment. Sericytochromatia, the proposed name of the paraphyletic and most basal group, is the ancestor of both the non-photosynthetic group Melainabacteria and the photosynthetic cyanobacteria, also called Oxyphotobacteria. Cyanobacteria use photosynthetic pigments, such as carotenoids, phycobilins, and various forms of chlorophyll, which absorb energy from light. Unlike heterotrophic prokaryotes, cyanobacteria have internal membranes. These are flattened sacs called thylakoids where photosynthesis is performed. Phototrophic eukaryotes such as green plants perform photosynthesis in plast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroplast
A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it in the energy-storage molecules ATP and NADPH while freeing oxygen from water in the cells. The ATP and NADPH is then used to make organic molecules from carbon dioxide in a process known as the Calvin cycle. Chloroplasts carry out a number of other functions, including fatty acid synthesis, amino acid synthesis, and the immune response in plants. The number of chloroplasts per cell varies from one, in unicellular algae, up to 100 in plants like ''Arabidopsis'' and wheat. A chloroplast is characterized by its two membranes and a high concentration of chlorophyll. Other plastid types, such as the leucoplast and the chromoplast, contain little chlorophyll and do not carry out photosynthesis. Chloroplasts are highly dynamic—they circulat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytosol
The cytosol, also known as cytoplasmic matrix or groundplasm, is one of the liquids found inside cells (intracellular fluid (ICF)). It is separated into compartments by membranes. For example, the mitochondrial matrix separates the mitochondrion into many compartments. In the eukaryotic cell, the cytosol is surrounded by the cell membrane and is part of the cytoplasm, which also comprises the mitochondria, plastids, and other organelles (but not their internal fluids and structures); the cell nucleus is separate. The cytosol is thus a liquid matrix around the organelles. In prokaryotes, most of the chemical reactions of metabolism take place in the cytosol, while a few take place in membranes or in the periplasmic space. In eukaryotes, while many metabolic pathways still occur in the cytosol, others take place within organelles. The cytosol is a complex mixture of substances dissolved in water. Although water forms the large majority of the cytosol, its structure and prope ... [...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] |
Ferredoxin
Ferredoxins (from Latin ''ferrum'': iron + redox, often abbreviated "fd") are iron–sulfur proteins that mediate electron transfer in a range of metabolic reactions. The term "ferredoxin" was coined by D.C. Wharton of the DuPont Co. and applied to the "iron protein" first purified in 1962 by Mortenson, Valentine, and Carnahan from the anaerobic bacterium '' Clostridium pasteurianum''. Another redox protein, isolated from spinach chloroplasts, was termed "chloroplast ferredoxin". The chloroplast ferredoxin is involved in both cyclic and non-cyclic photophosphorylation reactions of photosynthesis. In non-cyclic photophosphorylation, ferredoxin is the last electron acceptor thus reducing the enzyme NADP+ reductase. It accepts electrons produced from sunlight- excited chlorophyll and transfers them to the enzyme ferredoxin: NADP+ oxidoreductase . Ferredoxins are small proteins containing iron and sulfur atoms organized as iron–sulfur clusters. These biological " capacitors" can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glutamate
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 solu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Archaea")
