Astronomers have spotted the organic molecule methanol surrounding the icy moon.
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Vinyl cyanide is a complex organic molecule capable of forming cell membrane-like spheres.
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A popular theory was that AMEs were being produced by an organic molecule known as polycyclic aromatic hydrocarbons (PAHs).
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Their look depends on which metal ion or cluster of metal ions (connectors) are linked by whichever organic molecule (straws).
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The study also found that Arrokoth is rich in methanol ice, a simpler organic molecule, and surprisingly little, if any, water ice.
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Chemical structure of NMN (image: Edgar181)NMN is an organic molecule, or nucleotide, found in a variety of nutritional sources, including milk.
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This year, researchers detected vinyl cyanide, a complex organic molecule capable of forming cell membrane-like spheres that may lead to life.
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Postberg and the rest of the researchers have identified large organic molecule fragments in ice grains that were spewed from geysers on Enceladus.
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Searching for life beyond Earth means searching for organic compounds (like the organic matter in the mudstone) and molecules (methane is considered the simplest organic molecule).
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The European Space Agency's Rosalind Franklin rover, due on Mars next March, will bring a Mars Organic Molecule Analyzer that can collect and analyze larger molecules.
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NASA is involved as well; for example, the American space agency is providing key components for the rover&aposs main astrobiology instrument, the Mars Organic Molecule Analyzer.
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Detecting this organic molecule in the atmosphere, combined with the finding of organic compounds in the soil, has strong implications about potential life on Mars in its past.
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Schelter's lab has designed an organic molecule, called a ligand, which binds to neodymium and dysprosium, allowing the metals to be separated in minutes via a simple filtration process.
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In 1828 the German chemist Friedrich Wöhler synthesized urea, an organic molecule otherwise found in urine that primarily serves to remove nitrogen produced in metabolic reactions from the body.
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They're all essentially the same, except the organic molecule is switched out: poly(p-phenylene) for blue light, polythiophene for red light, and poly(p-phenylene vinylene) for green light.
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It's based on a machine learning system that has ingested millions of patents and known chemical processes, allowing it to connect the dots and propose a method for creating pretty much any complex organic molecule.
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Image: NASA/JPL-Caltech/ESA/CXC/STScIUsing some of the world's most sophisticated telescopes, a pair of astronomers has discovered a first-of-its-kind organic molecule in an enormous star-forming cloud thousands of light years away.
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NASA Jet Propulsion Laboratory scientists recreated this environment using iron, ammonia, and the simple organic molecule pyruvate dissolved into water from which all of the dissolved oxygen had been removed (to simulate the anoxic conditions of the early Earth).
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Writing today in Science Advances, Huang and his colleagues describe their method for degrading polyethylene at temperatures as low as 150 degrees Celsius, by adding an organometallic catalyst—a small, commercially available organic molecule doped with the metal iridium—to the reaction.
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Nonetheless, with organics confirmed to be present in the Martian soil, the search is on to understand their origin, as well as that of gaseous methane -- the simplest organic molecule -- that Curiosity has been sniffing repeatedly in the atmosphere, coming from an as yet unidentified source.
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In metathesis, these two double bonds combine and split to make four single bonds. The single bonds form a ring that connects the metal catalyst, the organic fragment, and the two parts of the organic molecule. The metal catalyst then breaks off from the ring, carrying away part of the organic molecule. This process leaves the fragment attached to the remainder of the organic molecule with a double bond, forming a new organic compound.
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A neurochemical is a small organic molecule or peptide that participates in neural activity. The science of neurochemistry studies the functions of neurochemicals.
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Pipecolic acid (piperidine-2-carboxylic acid) is a small organic molecule which accumulates in pipecolic acidemia. It is a carboxylic acid of piperidine.
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In biology, glycosylation is the process by which a carbohydrate is covalently attached to an organic molecule, creating structures such as glycoproteins and glycolipids..
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10,000-fold increased intensity can be obtained compared to NMR signals of the same organic molecule without PHIP and thus only "thermal" polarization at room temperature.
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Amination is the process by which an amine group is introduced into an organic molecule. This type of reaction is important because organonitrogen compounds are pervasive.
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Imidazoquinoline, and locations of possible modification to form its derivatives. Imidazoquinoline is a tricyclic organic molecule; its derivatives and compounds are often used for antiviral and antiallergic creams.
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2,3,4-Pentanetrione (or IUPAC name pentane-2,3,4-trione, triketopentane or dimethyl triketone) is the simplest linear triketone, a ketone with three C=O groups. It is an organic molecule with formula CH3COCOCOCH3.
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Metalation (Alt. spelling: Metallation) is a chemical reaction which involves the bonding of a metal atom to what is typically an organic molecule to form a new compound. This reaction usually involves the replacement of a halogen atom in an organic molecule with a metal atom to form an organometallic compound. In the laboratory, metalation is commonly used to activate organic molecules during the formation of C—X bonds (where X is typically Carbon, Oxygen, or Nitrogen), which are necessary for the synthesis of many organic molecules.
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In the early 1970s Chauvin achieved a breakthrough when he described the mechanism by which a metal atom bound to a carbon atom in one group of atoms causes the group to shift places with a group of atoms in another molecule and explained metathesis in detail. He showed that the reaction involves two double bonds. One of the double bonds connects two parts of an organic molecule. The other double bond connects a metal-based catalyst to a fragment of an organic molecule.
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Schematic drawing of artificial phosphorylase An artificial enzyme is a synthetic, organic molecule or ion that recreate some function of an enzyme. The area promises to deliver catalysis at rates and selectivity observed in many enzymes.
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Cotter was also a co-investigator on the Mars Organic Molecule Analyzer (MOMA) project, developing a miniaturized, low power consumption ion trap/time-of-flight mass spectrometer that was to be deployed with the ExoMars rover.
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The calibration should be examined periodically to certify nothing has changed in the GC over time. In the internal standard method, the sample is doped with a known amount of some organic molecule and the amount of all other species can be derived from their relative response to the internal standard (IS). The IS can be any organic molecule and should be chosen for ease of use and compatibility with the compounds in the mixture. For example, one could add 0.01 g of methanol as the IS to 0.9 g of gasoline.
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A related area of research is to develop smaller rectifiers, because a smaller device has a higher cutoff frequency. Research projects are attempting to develop a unimolecular rectifier, a single organic molecule that would function as a rectifier.
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1,3 BAC chemically 1,3-bis(aminomethyl) cyclohexane is an organic molecule belonging to the sub class cycloaliphatic amine. It has the CAS Registry Number of 2579-20-6. Its key use is as an epoxy resin curing agent.
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Formyl cyanide is a simple organic molecule with formula HCOCN. It is simultaneously a nitrile and a carbonyl. Formyl cyanide is the simplest member of the acyl cyanide family. It is known to occur in space in the Sgr B2 molecular cloud.
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The most common organic molecule to be used as a photochrome is diarylethene. Other examples of photoswitchable proteins include PADRON-C, rs-FastLIME-s and bs-DRONPA-s, which can be used in plant and mammalian cells alike to watch cells move into different environments.
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Anisyl sulfanyl methyl isocyanide (Asmic)Fleming, F. F. Composition, Synthesis, and Use of Isonitriles. U.S. Patent 8,269,032, Sept 18, 2012. is an organic molecule that contains an isocyanide group and an ortho-methoxy-phenyl sulfide group. Asmic can be used to synthesize tri-substituted isocyanides.
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Elongase is a generic term for an enzyme that catalyzes carbon chain extension of an organic molecule, especially a fatty acid. Elongases play a variety of roles in mammalian organisms, accounting for changes in tissue function, lipid regulation, and the overall physiology of an organism.
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Breaking down a protein into amino acids, or a triglyceride into fatty acids, or a disaccharide into monosaccharides are all hydrolysis or catabolic reactions. Second, oxidation reactions involve the removal of hydrogens and electrons from an organic molecule."Lehninger's Principles of Biochemistry", 4th edition, pp. 616, 2004.
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IP3 is an organic molecule with a molecular mass of 420.10 g/mol. Its empirical formula is C6H15O15P3. It is composed of an inositol ring with three phosphate groups bound at the 1, 4, and 5 carbon positions, and three hydroxyl groups bound at positions 2, 3, and 6.
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Many methods have been developed for influencing the stereoselectivity of the Diels–Alder reaction, such as the use of chiral auxiliaries, catalysis by chiral Lewis acids, and small organic molecule catalysts. Evans' oxazolidinones, oxazaborolidines, bis-oxazoline–copper chelates, imidazoline catalysis, and many other methodologies exist for effecting diastereo- and enantioselective Diels-Alder reactions.
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Naphthalocyanine is a cross-shaped organic molecule consisting of 48 carbon, 8 nitrogen and 26 hydrogen atoms, it is a derivative of phthalocyanine. IBM Research labs used it for developing single-molecule logic switches and visualizing charge distribution in a single molecule. Naphthalocyanine derivatives have a potential use in photodynamic cancer treatment.
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A covalent bond joining atoms in an organic molecule consists of a group of two electrons. Such a group is referred to as an electron pair. Reactions in organic chemistry proceed through the sequential breaking and formation of such bonds. Organic chemists recognize two processes for the breaking of a chemical bond.
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Glycogen's properties allow it to be metabolized more quickly, which suits the active lives of moving animals. Cellulose and chitin are examples of structural polysaccharides. Cellulose is used in the cell walls of plants and other organisms, and is said to be the most abundant organic molecule on Earth.N.A.Campbell (1996) Biology (4th edition).
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Toluidine blue solution is used in testing for lignin, a complex organic molecule that bonds to cellulose fibres and strengthens and hardens the cell walls in plants. A positive toluidine blue test causes the solution to turn from blue to pink. A similar test can be performed with phloroglucinol-HCl solution, which turns red.
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A functional group is very similar to a chemical species and a chemical group. A chemical group or chemical species exhibits a distinctive reaction behavior or a distinctive spectral signal when analyzed by various spectroscopic methods. These three groupings are often used to describe the groups of elements that exist within an organic molecule.
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Bullvalene is a hydrocarbon with the chemical formula C10H10. The molecule has a cage-like structure formed by the fusion of one cyclopropane and three cycloheptadiene rings. Bullvalene is unusual as an organic molecule due to the C−C and C=C bonds forming and breaking rapidly on the NMR timescale; this property makes it a fluxional molecule.
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Isobutyronitrile is a complex organic molecule that has been recently found in several meteorites arrived from space. The singularity of this chemical is due to the fact that it is the only one among the molecules arriving from the universe that has a branched, rather than straight, carbon backbone which is larger than usual, in comparison with others.
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NMR spectroscopy uses the net spin of nuclei in a substance upon energy absorption to identify molecules. This has now become a standard spectroscopic tool within synthetic chemistry. One major use of NMR is to determine the bond connectivity within an organic molecule. NMR imaging also uses the net spin of nuclei (commonly protons) for imaging.
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3,9-Divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane (DVTOSU) is a bicyclic organic molecule having a central quaternary carbon atom (a spiro atom) with which two alicyclic rings are linked, each comprising five atoms. DVTOSU is a diallyl acetal and the precursor for the isomeric ketene acetal monomer 3,9-diethylidene-2,4,8,10-tetraoxaspiro[5.5]undecane (DETOSU) which is a building block for polyorthoesters.
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Fischer projection of D-Glyceraldehyde Projection of a tetrahedral molecule onto a planar surface. Visualizing a Fischer projection. The Fischer projection, devised by Emil Fischer in 1891, is a two-dimensional representation of a three-dimensional organic molecule by projection. Fischer projections were originally proposed for the depiction of carbohydrates and used by chemists, particularly in organic chemistry and biochemistry.
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Woodward−Fieser rules estimate the shift in wavelength of maximum absorption for several auxochromes attached to a conjugated system in an organic molecule. An auxochrome helps a dye to bind to the object that is to be colored. Electrolytic dissociation of the auxochrome group helps in binding and it is due to this reason a basic substance takes an acidic dye.
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Dehydrogenation is the a chemical reaction that involves the removal of hydrogen, usually from an organic molecule. It is the reverse of hydrogenation. Dehydrogenation is important, both as a useful reaction and a serious problem. At its simplest, it is useful way of converting alkanes, which are relatively inert and thus low-valued, to olefins, which are reactive and thus more valuable.
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Photodynamic therapy (PDT) is a method for treating cancer. In this technique, an organic molecule with a good triplet quantum yield is excited so that the triplet state of this molecule interacts with oxygen. The ground state of oxygen has triplet character. This leads to triplet-triplet annihilation, which gives rise to singlet oxygen, which in turn attacks cancerous cells.
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In this study, the resonance of one population of protons (1H) in an organic molecule was enhanced when a second distinct population of protons in the same organic molecule was saturated by RF irradiation. The application of the NOE was used by Anet and Bourn in 1965 to confirm the assignments of the NMR resonances for β,β-dimethylacrylic acid and dimethyl formamide showed that conformation and configuration information about organic molecules can be obtained. Bell and Saunders reported direct correlation between NOE enhancements and internuclear distances in 1970 while quantitative measurements of internuclear distances in molecules with three or more spins was reported by Schirmer et al. Richard R. Ernst was awarded the 1991 Nobel Prize in Chemistry for developing Fourier transform and two- dimensional NMR spectroscopy, which was soon adapted to the measurement of the NOE, particularly in large biological molecules.
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Alkylation occurs when a molecule replaces a hydrogen atom with an alkyl group that generally comes from an organic molecule. Alkyl groups that are found naturally occurring in the environment are organometallic compounds. Organometallic compounds generally contain a methyl, ethyl, or butyl derivative which is the alkyl group that replaces the hydrogen. Other organic compounds, such as methanol, can provide alkyl groups for alkylation.
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Formaldehyde appears to be a useful probe in astrochemistry due to prominence of the 110←111 and 211←212 K-doublet transitions. It was the first polyatomic organic molecule detected in the interstellar medium. Since its initial detection in 1969, it has been observed in many regions of the galaxy. Because of the widespread interest in interstellar formaldehyde, it has been extensively studied, yielding new extragalactic sources.
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Simple ladderane structure In chemistry, a ladderane is an organic molecule containing two or more fused cyclobutane rings. The name arises from the resemblance of a series of fused cyclobutane rings to a ladder. Numerous synthetic approaches have been developed for the synthesis of ladderane compounds of various lengths. The mechanisms often involve [2 + 2] photocycloadditions, a useful reaction for creating strained 4-membered rings.
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These gophers are able to alter the mineral availability, organic molecule concentration, texture, and moisture content of soil. This can be either a benefit or a nuisance depending on the soil condition and usage. In arid or semi-arid environments, these changes enhance vegetation growth and soil quality. They are thought to be able to help generate and regenerate prairie lands that have degraded.
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Since the electron can have spin up and spin down and can rotate about the circle in both directions all of the energy levels except the lowest are doubly degenerate. The above shows the π-electronic energy levels of an organic molecule. Absorption of radiation is followed by molecular vibration to the S1 state. This is followed by a de-excitation to the S0 state called fluorescence.
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Even if there is no oxygen present, glycolysis can continue to generate ATP. However, for glycolysis to continue to produce ATP, there must be NAD+ present, which is responsible for oxidizing glucose. This is achieved by recycling NADH back to NAD+. When NAD+ is reduced to NADH, the electrons from NADH are eventually transferred to a separate organic molecule, transforming NADH back to NAD+.
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A generic oxaziridine derivative. An oxaziridine is an organic molecule that features a three-membered heterocycle containing oxygen, nitrogen, and carbon. In their largest application, oxaziridines are intermediates in the industrial production of hydrazine. Oxaziridine derivatives are also used as specialized reagents in organic chemistry for a variety of oxidations, including alpha hydroxylation of enolates, epoxidation and aziridination of olefins, and other heteroatom transfer reactions.
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She is a Professor of Astronomy at Harvard University and leader of the Öberg Astrochemistry Group at the Harvard-Smithsonian Center for Astrophysics. She is best known for her work studying star formation, planet formation, and stellar evolution in relation to organic molecules, which are necessary to determine the origins of life on Earth and elsewhere. In April 2015, Öberg's group discovered the first complex organic molecule in a protoplanetary disk.
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Several mechanisms of organic molecule synthesis have been investigated. Polyphosphates cause polymerization of amino acids into peptides. They are also logical precursors in the synthesis of such key biochemical compounds as adenosine triphosphate (ATP). A key issue seems to be that calcium reacts with soluble phosphate to form insoluble calcium phosphate (apatite), so some plausible mechanism must be found to keep calcium ions from causing precipitation of phosphate.
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Lofendazam is an organic molecule which is a benzodiazepine derivative. Lofendazam is a 1,5-benzodiazepine, with the nitrogen atoms located at positions 1 and 5 of the diazepine ring; therefore, lofendazam is most closely related to other 1,5-benzodiazepines such as clobazam. Lofendazam as a human pharmaceutical has sedative and anxiolytic effects similar to those produced by other benzodiazepine derivatives. It is an active metabolite of another benzodiazepine, arfendazam.
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NOBIN (2-amino-2'-hydroxy-1,1'-binaphthyl) is an organic molecule used for asymmetric catalysis. NOBIN is related to BINOL and other analogs by both having a chiral axis and being a scaffold for certain chemical reactions. NOBIN is an excellent catalyst for the aldol reaction producing reliable products, good yields, and excellent diastereoselectivity. Though rotation around the bond joining the rings is limited by the hydrogen atoms, enantiomerically pure NOBIN may racemize upon heating.
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The second stage of catalysis is the resolution of the acyl-enzyme intermediate by the attack of a second substrate. If this substrate is water then the result is hydrolysis; if it is an organic molecule then the result is transfer of that molecule onto the first substrate. Attack by this second substrate forms a new tetrahedral intermediate, which resolves by ejecting the enzyme's nucleophile, releasing the second product and regenerating free enzyme.
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Structure and nomenclature of all second-row 1,3-dipoles consisting of carbon, nitrogen and oxygen centers. The dipoles are categorized as allyl-type or propargyl/allenyl-type based on the geometry of the central atom. A 1,3-dipole is an organic molecule that can be represented as either an allyl-type or a propargyl/allenyl-type zwitterionic octet/sextet structures. Both types of 1,3-dipoles share four electrons in the π-system over three atoms.
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Adenine Thymine Guanine Cytosine Uracil A nitrogenous base, or nitrogen- containing base, is an organic molecule with a nitrogen atom that has the chemical properties of a base. The main biological function of a nitrogenous base is to bond nucleic acids together. A nitrogenous base owes its basic properties to the lone pair of electrons of a nitrogen atom. Nitrogenous bases are typically classified as the derivatives of two parent compounds, pyrimidine and purine.
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Bacterial luciferase consists of two subunits, depicted by the red and blue regions.The chemical reaction that is responsible for bio-luminescence is catalyzed by the enzyme luciferase. In the presence of oxygen, luciferase catalyzes the oxidation of an organic molecule called luciferin. Though bio-luminescence across a diverse range of organisms such as bacteria, insects, and dinoflagellates function in this general manner (utilizing luciferase and luciferin), there are different types of luciferin-luciferase systems.
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Cholesterol (from the Ancient Greek chole- (bile) and stereos (solid), followed by the chemical suffix -ol for an alcohol) is an organic molecule. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell membranes. Cholesterol also serves as a precursor for the biosynthesis of steroid hormones, bile acid and vitamin D. Cholesterol is the principal sterol synthesized by all animals.
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The simplest form of an organic molecule is the hydrocarbon—a large family of organic molecules that are composed of hydrogen atoms bonded to a chain of carbon atoms. A hydrocarbon backbone can be substituted by other atoms, known as heteroatoms. Common heteroatoms that appear in organic compounds include oxygen, nitrogen, sulfur, phosphorus, and the nonradioactive halogens, as well as the metals lithium and magnesium. Organic compounds containing bonds to metal are known as organometallic compounds (see below).
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The validated and curated CSD files can be exported in a wide range of formats, including CIF, MOL, Mol2, PDB, SHELX and XMol, using tools in the CSD System. The CCDC uses two different codes to distinguish between the deposited dataset and the curated CSD entry. For example, one specific ‘CSD Communication’ of an organic molecule was deposited with the CCDC and assigned the deposition number 'CCDC-991327.' This allows free public access to the data as deposited.
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Therefore, the authors developed a new method to fabricate functional, cell-lining and perfusable microchannels inside 3D hydrogel. The vessel endothelial and renal epithelial cells are cultured inside hydrogel microchannel and form cellular coverage to mimic vessels and tubules, respectively. They employed confocal microscope to examine the passive diffusion of one small organic molecule (usually drugs) between the vessels and tubules in hydrogel. The study demonstrates the beneficial potential to mimic renal physiology for regenerative medicine and drug screening.
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1,3-Bisphosphoglyceric acid (1,3-Bisphosphoglycerate or 1,3BPG) is a 3-carbon organic molecule present in most, if not all, living organisms. It primarily exists as a metabolic intermediate in both glycolysis during respiration and the Calvin cycle during photosynthesis. 1,3BPG is a transitional stage between glycerate 3-phosphate and glyceraldehyde 3-phosphate during the fixation/reduction of CO2. 1,3BPG is also a precursor to 2,3-bisphosphoglycerate which in turn is a reaction intermediate in the glycolytic pathway.
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In alcohol fermentation, when a glucose molecule is oxidized, ethanol (ethyl alcohol) and carbon dioxide are byproducts. The organic molecule that is responsible for renewing the NAD+ supply in this type of fermentation is the pyruvate from glycolysis. Each pyruvate releases a carbon dioxide molecule, turning into acetaldehyde. The acetaldehyde is then reduced by the NADH produced from glycolysis, forming the alcohol waste product, ethanol, and forming NAD+, thereby replenishing its supply for glycolysis to continue producing ATP.
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The extended Hückel method is a semiempirical quantum chemistry method, developed by Roald Hoffmann since 1963. It is based on the Hückel method but, while the original Hückel method only considers pi orbitals, the extended method also includes the sigma orbitals. The extended Hückel method can be used for determining the molecular orbitals, but it is not very successful in determining the structural geometry of an organic molecule. It can however determine the relative energy of different geometrical configurations.
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It connotes an organic molecule or an unformulated compound having surface-active properties. All three classes of surfactants, namely, anionic, cationic and nonionic surfactants, have been successfully tried as drag-reducing agents. Knowing what will create the ideal drag reducer is key in this process. Ideal molecules have a high molecular weight, shear degradation resistance, are quick to dissolve in whatever is in the pipe, and have low degradation in heat, light, chemicals, and biological areas.
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Like inorganic carbon, there are two main forms of organic carbon found in the ocean (dissolved and particulate). Dissolved organic carbon (DOC) is defined operationally as any organic molecule that can pass through a 0.2 µm filter. DOC can be converted into particulate organic carbon through heterotrophy and it can also be converted back to dissolved inorganic carbon (DIC) through respiration. Those organic carbon molecules being captured on a filter are defined as particulate organic carbon (POC).
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In 1926, he began work as a researcher at the Royal Institution in London, under the tutelage of Bragg. He continued to work on sesquiterpene derivatives, but also shifted his attention to physics. In 1928 he obtained a post in physics at the University of Michigan in the United States, but returned to the Royal Institution at the Davy-Faraday Laboratory in 1930. During that time, he solved many small, organic molecule structures by X-ray crystallography.
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EPR spectrum of a spin label A spin label (SL) is an organic molecule which possesses an unpaired electron, usually on a nitrogen atom, and the ability to bind to another molecule. Spin labels are normally used as tools for probing proteins or biological membrane-local dynamics using electron paramagnetic resonance spectroscopy. The site-directed spin labeling (SDSL) technique allows one to monitor a specific region within a protein. In protein structure examinations, amino acid-specific SLs can be used.
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In the early 1950s, Woodward, along with the British chemist Geoffrey Wilkinson, then at Harvard, postulated a novel structure for ferrocene, a compound consisting of a combination of an organic molecule with iron. This marked the beginning of the field of transition metal organometallic chemistry which grew into an industrially very significant field. Wilkinson won the Nobel Prize for this work in 1973, along with Ernst Otto Fischer. Some historians think that Woodward should have shared this prize along with Wilkinson.
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Interstellar formaldehyde was the first organic molecule detected in the interstellar medium. Perhaps the most powerful technique for detection of individual chemical species is radio astronomy, which has resulted in the detection of over a hundred interstellar species, including radicals and ions, and organic (i.e. carbon-based) compounds, such as alcohols, acids, aldehydes, and ketones. One of the most abundant interstellar molecules, and among the easiest to detect with radio waves (due to its strong electric dipole moment), is CO (carbon monoxide).
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Nitrates typically provide the required oxygen to burn the carbon and hydrogen fuel. High explosives tend to have the oxygen, carbon and hydrogen contained in one organic molecule, and less sensitive explosives like ANFO are combinations of fuel (carbon and hydrogen fuel oil) and ammonium nitrate. A sensitizer such as powdered aluminum may be added to an explosive to increase the energy of the detonation. Once detonated, the nitrogen portion of the explosive formulation emerges as nitrogen gas and toxic nitric oxides.
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The Mars Organic Molecule Analyzer (MOMA) project is part of a collaboration to search for potential signatures of Martian life. Cotter was a deputy principal investigator and responsible for the design and development of a low-power, ion trap-time-of-flight mass spectrometer to be deployed with the ESA ExoMars rover. However, in February 2012, NASA cancelled its participation in the rover and defunded projects related to it. By November 2012 NASA reestablished the funding for the US part of MOMA.
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A more recent development is the use of chiral secondary amine catalysts. These secondary amines form transient enamines when exposed to ketones, which may react enantioselectively with suitable aldehyde electrophiles. The amine reacts with the carbonyl to form an enamine, the enamine acts as an enol-like nucleophile, and then the amine is released from the product all—the amine itself is a catalyst. This enamine catalysis method is a type of organocatalysis, since the catalyst is entirely based on a small organic molecule.
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In synthesis, metallated reagents are typically involved in nucleophilic substitution, single-electron-transfer (SET), and redox chemistry with functional groups on other molecules (including but not limited to ketones, aldehydes, and alkyl halides). Metallated molecules may also participate in acid-base chemistry, with one organometallic reagent deprotonating an organic molecule to create a new organometallic reagent. The most common classes of metallated compounds are organolithium reagents and Grignard reagents. However, other organometallic compounds — such as organozinc compounds — also experience common use in both laboratory and industrial applications.
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A molecule of water may be eliminated, for example, by the action of sulfuric acid. Another example is chloral hydrate, CCl3−CH(OH)2, which can be formed by reaction of water with chloral, CCl3−CH=O. Many organic molecules, as well as inorganic molecules, form crystals that incorporate water into the crystalline structure without chemical alteration of the organic molecule (water of crystallization). The sugar trehalose, for example, exists in both an anhydrous form (melting point 203 °C) and as a dihydrate (melting point 97 °C).
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A vitamin is an organic molecule (or a chemically closely related set of molecules, i.e. vitamers) that is an essential micronutrient which an organism needs in small quantities for the proper functioning of its metabolism. Essential nutrients cannot be synthesized in the organism, either at all or not in sufficient quantities, and therefore must be obtained through the diet. Vitamin C can be synthesized by some species but not by others; it is not a vitamin in the first instance but is in the second.
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9,10-Dithioanthracene (DTA) is an organic molecule and a derivative of anthracene with two thiol groups. In 2004 DTA molecules were demonstrated to be able to "walk" in a straight line (reportedly a first ) on a metal surface by, in effect, mimicking the bipedal motion of a human being. The sulfur- bearing functional groups on either side (referred to as "linkers") serve as the molecule's "feet". When the compound is heated on a flat copper surface, the linkers raise up, alternating from side to side, and propel the molecule forward.
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The Casparian strip, a cell wall outside the stele but within the root, prevents passive flow of water and nutrients, helping to regulate the uptake of nutrients and water. Xylem moves water and mineral ions within the plant and phloem accounts for organic molecule transportation. Water potential plays a key role in a plant's nutrient uptake. If the water potential is more negative within the plant than the surrounding soils, the nutrients will move from the region of higher solute concentration—in the soil—to the area of lower solute concentration - in the plant.
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MPP+ (1-methyl-4-phenylpyridinium) is a positively charged organic molecule with the chemical formula C12H12N+. It is a neurotoxin that acts by interfering with oxidative phosphorylation in mitochondria by inhibiting complex I, leading to the depletion of ATP and eventual cell death.PubChem Compound entry on MPP+ MPP+ arises in the body as the toxic metabolite of the closely related compound MPTP. MPTP is converted in the brain into MPP+ by the enzyme MAO-B, ultimately causing parkinsonism in primates by killing certain dopamine-producing neurons in the substantia nigra.
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Planets of Red Dwarf Stars May Face Oxygen Loss In 2001, sodium was detected in the atmosphere of HD 209458 b. In 2008, water, carbon monoxide, carbon dioxide and methaneNASA – Hubble Finds First Organic Molecule on an Exoplanet. NASA. 19 March 2008 were detected in the atmosphere of HD 189733 b. In 2013, water was detected in the atmospheres of HD 209458 b, XO-1b, WASP-12b, WASP-17b, and WASP-19b. In July 2014, NASA announced finding very dry atmospheres on three exoplanets (HD 189733b, HD 209458b, WASP-12b) orbiting Sun-like stars.
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Clathrate hydrates (also known as gas hydrates, gas clathrates, etc.) are water ice with gas molecules trapped within; they are a form of clathrate. An important example is methane hydrate (also known as gas hydrate, methane clathrate, etc.). Nonpolar molecules such as methane can form clathrate hydrates with water, especially under high pressure. Although there is no hydrogen bonding between water and guest molecules when methane is the guest molecule of the clathrate, guest–host hydrogen bonding often forms when the guest is a larger organic molecule such as tetrahydrofuran.
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A secondary organic aerosol (SOA) is a molecule produced via oxidation over several generations of a parent organic molecule. In contrast to primary organic aerosols, which are emitted directly from the biosphere, secondary organic aerosols are either formed via homogeneous nucleation through the successive oxidation of gas-phase organic compounds, or through condensation on pre-existing particles. These gas-phase species exert high vapor pressures, meaning they are volatile and stable in the gas-phase. Upon oxidation, the increased polarity, and thus reduced volatility, of the molecules results in a reduction of vapor pressure.
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Compared to other hydrocarbon fuels, methane produces less carbon dioxide for each unit of heat released. At about 891 kJ/mol, methane's heat of combustion is lower than that of any other hydrocarbon. However, it produces more heat per mass (55.7 kJ/g) than any other organic molecule due to its relatively large content of hydrogen, which accounts for 55% of the heat of combustion but contributes only 25% of the molecular mass of methane. In many cities, methane is piped into homes for domestic heating and cooking.
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Acridine orange is derived from the organic molecule acridine, which was first discovered by Carl Grabe and Heinrich Caro, who isolated acridine by boiling coal in Germany during the late nineteenth century. Acridine has antimicrobial factors useful in drug-resistant bacteria and isolating bacteria in various environments. Acridine orange in the mid- twentieth century was used to examine the microbial content found in soil and direct counts of aquatic bacteria. Additionally, the method of acridine orange direct count (AODC) proved useful in the enumeration of bacteria found within landfills.
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Being a powerful oxidizing acid, nitric acid reacts violently with many organic materials and the reactions may be explosive. The hydroxyl group will typically strip a hydrogen from the organic molecule to form water, and the remaining nitro group takes the hydrogen's place. Nitration of organic compounds with nitric acid is the primary method of synthesis of many common explosives, such as nitroglycerin and trinitrotoluene (TNT). As very many less stable byproducts are possible, these reactions must be carefully thermally controlled, and the byproducts removed to isolate the desired product.
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"Bpbp" is 2,6-bis(N,N-bis(2-pyridylmethyl)aminomethyl)-4-tert-butylphenolato. An analogy of the function of cobalt bound to their organic molecule was made to the function of iron and copper in metalloproteins used for respiration by animals. The nitrate anions in the crystal are exchanged with neutral dioxygen but remain in the crystal; other anions besides nitrate work similarly and exchange oxygen faster. 10 liters of crystals are "enough to suck up all the oxygen in a room", three times more oxygen than an equivalent sized steel tank.
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For example, paclitaxel (taxol), an organic molecule found in the Pacific yew tree, binds tightly to tubulin dimers and inhibits their assembly into microtubules in the cytoskeleton. Many natural poisons act as neurotoxins that can cause paralysis leading to death and have functions for defence against predators or in hunting and capturing prey. Some of these natural inhibitors, despite their toxic attributes, are valuable for therapeutic uses at lower doses. An example of a neurotoxin are the glycoalkaloids, from the plant species in the family Solanaceae (includes potato, tomato and eggplant), that are acetylcholinesterase inhibitors.
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Nitrosylation results in a molecule "R" adducted with the group N=O Nitrosylation is the general term for covalent incorporation of a nitric oxide "nitrosyl" moiety into another (usually organic) molecule. There are multiple chemical mechanisms by which this can be achieved; including biological enzymes and industrial processes. The biological functions of nitrosylation are particularly important as S-nitrosylation, the conjugation of NO to cysteine thiols in proteins, is an important part of cell signalling. Coordination of NO to transition metals to give metal nitrosyl complexes, is also referred to as nitrosylation.
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Like many other reef-dwelling organisms, L. arboreumhas applications in the medical field, many of which are unknown. A 2006 study showed that 83% of Red Sea Alcyonacean corals exhibited antimicrobial activity against a variety of marine bacteria found in the surrounding environment. As a means of combating microbial attacks, Red Sea Alcyonacean corals use antibiotic compounds as a chemical defense. A 2018 study specifically on L. arboreum was able to find and isolate a pseudoguaiane-type sesquiterpene compound, an organic molecule, litopharbol, which exhibits both antimicrobial and anticancer activity, and has direct applications to medicine.
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Since then, this branch of the field has advanced rapidly. Likewise, as it has grown possible to measure such properties directly, the theoretical predictions of the early workers have been confirmed substantially. The concept of molecular electronics was published in 1974 when Aviram and Ratner suggested an organic molecule that could work as a rectifier. Having both huge commercial and fundamental interest, much effort was put into proving its feasibility, and 16 years later in 1990, the first demonstration of an intrinsic molecular rectifier was realized by Ashwell and coworkers for a thin film of molecules.
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Cheng earned her BS in chemistry from Peking University, and a doctoral degree in synthetic chemistry from Alan Kozikowski at the University of Pittsburgh. Her work studied applications of nitrile oxides, for example cycloadditions to form C-glycosides, or utilization of nitrile oxides as precursors to functionalized heterocycles. While a postdoctoral scholar at Harvard, Cheng co-authored The Logic of Chemical Synthesis with Corey, the first three chapters of which explore computational and logic-based approaches to disassemble organic molecule "targets" (TGTs) through various transforms, leading to "retrons" and "synthons", e.g. simpler molecules that could be used to access the TGT.
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In organic chemistry, when a single organic molecule has two different functional groups, it is called a bifunctional molecule . A bifunctional molecule has the properties of two different types of functional groups, such as an alcohol (-OH), amide (CONH2), aldehyde (-CHO), nitrile (-CN) or carboxylic acid (-COOH). Many bifunctional molecules are used to produce medicines and catalysts, while others are used in condensation polymerization like polyester and polyamide. In organic molecules, functional groups are atoms or molecules that are responsible for the characteristic properties of that molecule, with the exceptions of double and triple bonds, which are also functional groups.
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He explained chemical processes in the body in terms of addition and subtraction of simple molecules from a larger organic molecule, a concept that Bird followed in his own work. But even the materialistic Liebig continued to invoke the vital force for processes inside living animal bodies. This seems to have been based on a belief that the entire living animal is required for these chemical processes to take place. Bird helped to dispel this kind of thinking by showing that specific chemistry is related to specific organs in the body rather than to the whole animal.
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As a hard base, water reacts readily with organic carbocations; for example in a hydration reaction, a hydroxyl group () and an acidic proton are added to the two carbon atoms bonded together in the carbon-carbon double bond, resulting in an alcohol. When addition of water to an organic molecule cleaves the molecule in two, hydrolysis is said to occur. Notable examples of hydrolysis are the saponification of fats and the digestion of proteins and polysaccharides. Water can also be a leaving group in SN2 substitution and E2 elimination reactions; the latter is then known as a dehydration reaction.
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One primary system that controls bioluminescence through regulation of the lux operon is quorum sensing, a conserved system across many microbial species that regulates gene expression in response to bacterial concentration. Quorum sensing functions through the production of an autoinducer, usually a small organic molecule, by individual cells. As cell populations increase, levels of autoinducers increase, and specific proteins that regulate transcription of genes bind to these autoinducers and alter gene expression. This system allows microbial cells to "communicate" amongst each other and coordinate behaviors like luminescence, which require large amounts of cells to produce an effect.
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5-Dehydro-m-xylylene (DMX) is an aromatic organic triradical and the first known organic molecule to violate Hund's Rule. Its electronic ground state is an open-shell doublet rather than a quartet; that is, the unpaired electrons in the three singly occupied molecular orbitals form low-spin state in which one electron has its spin-state opposed to the other two. The net result is that there is only one unopposed spin. Hund's rule would predict that the ground state would have all three radical electrons with the same spin-state as each other (none opposed), for a greater total spin.
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Depending on the amount of nitrogen dioxide present, fuming nitric acid is further characterized as red fuming nitric acid at concentrations above 86%, or white fuming nitric acid at concentrations above 95%. Nitric acid is the primary reagent used for nitration – the addition of a nitro group, typically to an organic molecule. While some resulting nitro compounds are shock- and thermally-sensitive explosives, a few are stable enough to be used in munitions and demolition, while others are still more stable and used as pigments in inks and dyes. Nitric acid is also commonly used as a strong oxidizing agent.
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The TEAM has been tested on various crystalline solids, resolving individual atoms in GaN ([211] orientation), germanium ([114]), gold ([111]) and others, and reaching the spatial resolution below 0.05 nm (about 0.045 nm). In the images of graphene—a single sheet of graphite—not only the atoms, but also the chemical bonds could be observed. A movie has been recorded inside the microscope showing hopping of individual carbon atoms around a hole punched in a graphene sheet. Similar pictures, resolving carbon atoms and bonds between them, have been independently produced for pentacene—a planar organic molecule consisting of five carbon rings—using a very different microscopy technique, atomic force microscopy (AFM).
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Carbon-13 (C13) nuclear magnetic resonance (most commonly known as carbon-13 NMR or 13C NMR or sometimes simply referred to as carbon NMR) is the application of nuclear magnetic resonance (NMR) spectroscopy to carbon. It is analogous to proton NMR ( NMR) and allows the identification of carbon atoms in an organic molecule just as proton NMR identifies hydrogen atoms. As such 13C NMR is an important tool in chemical structure elucidation in organic chemistry. 13C NMR detects only the isotope of carbon, whose natural abundance is only 1.1%, because the main carbon isotope, , is not detectable by NMR since its nucleus has zero spin.
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Etravirine is a second-generation non-nucleoside reverse transcriptase inhibitor (NNRTI), designed to be active against HIV with mutations that confer resistance to the two most commonly prescribed first-generation NNRTIs, mutation K103N for efavirenz and Y181C for nevirapine. This potency appears to be related to etravirine's flexibility as a molecule. Etravirine is a diarylpyrimidine (DAPY), a type of organic molecule with some conformational isomerism that can bind the enzyme reverse transcriptase in multiple conformations, allowing for a more robust interaction between etravirine and the enzyme, even in the presence of mutations. Other diarylpyrimidine- analogues are currently being used as anti-HIV agents, notably rilpivirine.
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Space-filling model representation of dioxygen (O2) molecule The common allotrope of elemental oxygen on Earth is called dioxygen, , the major part of the Earth's atmospheric oxygen (see Occurrence). O2 has a bond length of 121 pm and a bond energy of 498 kJ/mol, which is smaller than the energy of other double bonds or pairs of single bonds in the biosphere and responsible for the exothermic reaction of O2 with any organic molecule. Due to its energy content, O2 is used by complex forms of life, such as animals, in cellular respiration. Other aspects of are covered in the remainder of this article.
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The upregulation of phosphatase genes is significant in that it indicates that a significant portion of the phosphorus obtained by the fungi in some environments may be from organic molecule catabolism. It is important to note that once a mycorrhizal symbiosis is established the only phosphorus obtained by the plant comes through the fungal tissue. Additionally the large scale assisted transport of phosphorus from fungi to plant only occurs when the fungal pelotons are alive, once these structures start to degrade significant flow of phosphorus ceases. This classifies this pathway as biotrophic, meaning transfer of nutrients between two or more organisms that are both alive.
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H2TPP molecules by applying excess voltage to the tip of a scanning tunneling microscope (STAM, a); this removal alters the current-voltage (I-V) curves of TPP molecules, measured using the same STM tip, from diode-like (red curve in b) to resistor-like (green curve). Image (c) shows a row of TPP, H2TPP and TPP molecules. While scanning image (d), excess voltage was applied to H2TPP at the black dot, which instantly removed hydrogen, as shown in the bottom part of (d) and in the re-scan image (e). A unimolecular rectifier is a single organic molecule which functions as a rectifier (one-way conductor) of electric current.
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Some key developments in biology were the discovery of genetics; evolution through natural selection; the germ theory of disease and the application of the techniques of chemistry and physics at the level of the cell or organic molecule. Modern biology is divided into subdisciplines by the type of organism and by the scale being studied. Molecular biology is the study of the fundamental chemistry of life, while cellular biology is the examination of the cell; the basic building block of all life. At a higher level, anatomy and physiology look at the internal structures, and their functions, of an organism, while ecology looks at how various organisms interrelate.
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24-isopropyl cholestane is an organic molecule produced by specific sponges, protists and marine algae. The identification of this molecule at high abundances in Neoproterozoic rocks has been interpreted to reflect the presence of multicellular life prior to the rapid diversification and radiation of life during the Cambrian explosion. In this transitional period at the start of the Phanerozoic, single-celled organisms evolved to produce many of the evolutionary lineages present on Earth today. Interpreting 24-isopropyl cholestane in ancient rocks as indicating the presence of sponges before this rapid diversification event alters the traditional understanding of the evolution of multicellular life and the coupling of biology to changes in end-Neoproterozoic climate.
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Through the Innovation and New Ventures Office (INVO), Northwestern researchers disclosed 247 inventions, filed 270 patent applications, received 81 foreign and US patents, started 12 companies, and generated $79.8 million in licensing revenue in 2013. The bulk of the revenue has come from a patent on pregabalin, a synthesized organic molecule discovered by chemistry professor Richard Silverman, which ultimately was marketed as Lyrica, a drug sold by Pfizer, to combat epilepsy, neuropathic pain, and fibromyalgia. INVO has been involved in creating a number of centers, including the Center for Developmental Therapeutics (CDT) and the Center for Device Development (CD2).Center for Device Development It has also helped form over 50 startup companies based on Northwestern technologies.
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The interaction between an excited photocatalyst and organic molecule can show a diverse sample of reactive intermediates that can be manipulated to form a synthetic bond construction. This impacts the photocatalyst and the photoactivation steps such as the interaction with the excited state of the photocatalyst or controlling the rate and selectivity of the photoactivation steps. Additionally, Yoon takes a dual approach to the asymmetric of enantioselective [2+2] photocycloadditions by using visible light that can absorb transition metal and a Lewis acid cocatalyst. Yoon was able to see that each catalyst can be enabled to be independent resulting in a broader scope and greater flexibility and efficiency in enantioselective photochemical cycloadditions.
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As late as the 1840s, and despite Friedrich Wöhler's synthesis of urea in 1828, some chemists still believed in the doctrine of vitalism, according to which a special life-force was necessary to create "organic" (i.e., in its original meaning, biologically derived) compounds. Kolbe promoted the idea that organic compounds could be derived from substances clearly sourced from outside this "organic" context, directly or indirectly, by substitution processes. (Hence, while by modern definitions, he was converting one organic molecule to another, by the parlance of his era, he was converting "inorganic"—anorganisch—substances into "organic" ones only thought accessible through vital processes.) He validated his theory by converting carbon disulfide to acetic acid in several steps (1843–45).
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He took a strong interest in NAVF major Research program on marine pollution and built up a team of specialists in oil chemistry at the University of Bergen, together with younger employees. Later he focused on pollution of lakes, and here his knowledge of chemistry came to its right, when he extracted new knowledge from the previously published data. Aksnes was a popular lecturer, and all his students at the basic course in organic chemistry remember his loudly, involved explanations about organic molecule that moves and reacts. As a student mentor, he was always interested in the work of the students, and he asked critical questions that helped developing critical thinking and expanded the mind of the student.
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The positive charges of the ions that enter the cell down its electrochemical gradient change the cell's membrane potential, cause depolarization, and lead to the release of the neurotransmitter glutamate. Glutamate can depolarize some neurons and hyperpolarize others, allowing photoreceptors to interact in an antagonistic manner. When light hits photoreceptive pigments within the photoreceptor cell, the pigment changes shape. The pigment, called rhodopsin (conopsin is found in cone cells) comprises a large protein called opsin (situated in the plasma membrane), attached to which is a covalently bound prosthetic group: an organic molecule called retinal (a derivative of vitamin A). The retinal exists in the 11-cis-retinal form when in the dark, and stimulation by light causes its structure to change to all-trans-retinal.
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LigandScout is computer software that allows creating three-dimensional (3D) pharmacophore models from structural data of macromolecule–ligand complexes, or from training and test sets of organic molecules. It incorporates a complete definition of 3D chemical features (such as hydrogen bond donors, acceptors, lipophilic areas, positively and negatively ionizable chemical groups) that describe the interaction of a bound small organic molecule (ligand) and the surrounding binding site of the macromolecule. These pharmacophores can be overlaid and superimposed using a pattern-matching based alignment algorithm that is solely based on pharmacophoric feature points instead of chemical structure. From such an overlay, shared features can be interpolated to create a so-called shared-feature pharmacophore that shares all common interactions of several binding sites/ligands or extended to create a so-called merged-feature pharmacophore.
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Dimethylmercury currently has few applications because of the risks involved. As with many methyl- organometallics, it is a methylating agent that can donate its methyl groups to an organic molecule; however, the development of less acutely toxic nucleophiles such as dimethylzinc and trimethylaluminium, and the subsequent introduction of Grignard reagents (organometallic halides), has essentially rendered this compound obsolete in organic chemistry. It was formerly studied for reactions in which the methylmercury cation was bonded to the target molecule, forming potent bactericides; however, the bioaccumulation and ultimate toxicity of methylmercury has largely led it to be abandoned for this purpose in favor of the less toxic diethylmercury and ethylmercury compounds, which perform a similar function without the bioaccumulation hazard. In toxicology, it was formerly used as a reference toxin.
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In a biological context chlorine behaves similarly to other atoms in the halogen chemical series, and thus reductive dechlorination can be considered to fall within a somewhat broader class of biological reactions known as reductive dehalogenation reactions, in which the removal of a halogen substituent from an organic molecule occurs with a simultaneous addition of electrons to the molecule. This can be further subdivided into two types of reaction processes, the first of which, hydrogenolysis, is the replacement of the halogen atom with a hydrogen atom. The second, vicinal reduction (sometimes called, dihaloelimination), involves the removal of two halogen atoms that are adjacent on the same alkane or alkene molecule, leading to the formation of an additional carbon-carbon bond. Biological reductive dechlorination is often catalyzed by certain species of bacteria.
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Conventionally, mass spectrometry, such as Gas Chromatography-Mass Spectrometry(GC-MS) and Gas Chromatography -Time Of Flight(GC-TOF), is a common technique for analyzing isotopically labeled molecules. This method involves ionizing and analyzing isotopologues of an intact organic molecule of interest rather than its products of pyrolysis or conversion. However, it does not work for natural abundance hydrogen isotopes because conventional mass spectrometers do not have enough mass-resolving power to measure the 13C/D isotopologues of intact organic molecules or molecular fragments at natural abundance. For example, to resolve the single D substituted isotopologue peak of any hydrocarbons you will at have to be able to at least exclude single 13C substituted isotopologue peak, which sits at the same cardinal mass yet 0.0029 AMU lighter and is of orders of magnitude more abundant.
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The pigment, called iodopsin or rhodopsin, consists of large proteins called opsin (situated in the plasma membrane), attached to a covalently bound prosthetic group: an organic molecule called retinal (a derivative of vitamin A). The retinal exists in the 11-cis-retinal form when in the dark, and stimulation by light causes its structure to change to all-trans-retinal. This structural change causes opsin (a G protein-coupled receptor) to activate its G protein transducin, which leads to the activation of cGMP phosphodiesterase, which breaks cGMP down into 5'-GMP. Reduction in cGMP allows the ion channels to close, preventing the influx of positive ions, hyperpolarizing the cell, and stopping the release of neurotransmitters. The entire process by which light initiates a sensory response is called visual phototransduction.
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In 1933, Aleksander Jabłoński published his conclusion that the extended lifetime of phosphorescence was due to a metastable excited state at an energy lower than the state first achieved upon excitation. Based upon this research, Gilbert Lewis and coworkers, during their investigation of organic molecule luminescence in the 1940s, concluded that this metastable energy state corresponded to the triplet electron configuration. The triplet state was confirmed by Lewis via application of a magnetic field to the excited phosphor, as only the metastable state would have a long enough lifetime to be analyzed and the phosphor would have only responded if it was paramagnetic due to it having at least one unpaired electron. Their proposed pathway of phosphorescence included the forbidden spin transition occurring when the potential energy curves of the singlet excited state and the triplet excited state crossed, from which the term intersystem crossing arose.
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Tetrathiafulvalene (TTF) center typical in organic superconductors A Bechgaard salt is any one of a number of organic charge-transfer complexes that exhibit superconductivity at low temperatures.The Physics of Organic Superconductors and Conductors, A.G. Lebed (Ed.), (Springer Series in Materials Science , Vol. 110, 2008), They are named for chemist Klaus Bechgaard, who was one of the first scientists to synthesize them and demonstrate their superconductivity with the help of physicist Denis Jérôme.Jérôme D., Mazaud A., Ribault M., and Bechgaard K., "Superconductivity in a synthetic organic conductor (TMTSF)2PF6," Journal de Physique Lettres 41, 4 (1980): L95-98 Most Bechgaard salt superconductors are extremely low temperature, and lose superconductivity above the 1–2 K range, although the most successful compound in this class superconducts up to almost 12 K. All Bechgaard salts are formed using a small, planar organic molecule as an electron donor, with any of a number of electron acceptors [such as perchlorate (ClO4) or tetracyanoethylene (TCNE)].
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Dalton, by contrast, did not consider this possibility. Curiously, Avogadro considers only molecules containing even numbers of atoms; he does not say why odd numbers are left out. In 1826, building on the work of Avogadro, the French chemist Jean-Baptiste Dumas states: In coordination with these concepts, in 1833 the French chemist Marc Antoine Auguste Gaudin presented a clear account of Avogadro's hypothesis, regarding atomic weights, by making use of "volume diagrams", which clearly show both semi-correct molecular geometries, such as a linear water molecule, and correct molecular formulas, such as H2O: Marc Antoine Auguste Gaudin's volume diagrams of molecules in the gas phase (1833) In two papers outlining his "theory of atomicity of the elements" (1857–58), Friedrich August Kekulé was the first to offer a theory of how every atom in an organic molecule was bonded to every other atom. He proposed that carbon atoms were tetravalent, and could bond to themselves to form the carbon skeletons of organic molecules. In 1856, Scottish chemist Archibald Couper began research on the bromination of benzene at the laboratory of Charles Wurtz in Paris.
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