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  • redox reactions
  • The process of photorespiration, also known as C2 cycle, is also coupled to the dark reactions, as it results from an alternative reaction of the RuBisCO enzyme, and its final byproduct is also another glyceraldehyde-3-P. The Calvin cycle, Calvin-Benson-Bassham (CBB) cycle, reductive pentose phosphate cycle or C3 cycle is a series of biochemical redox reactions that take place in the stroma of chloroplast in photosynthetic organisms. (wikipedia.org)
  • Because this state of an electron is very unstable, the electron is transferred from one to another molecule creating a chain of redox reactions, called an electron transport chain (ETC). The electron flow goes from PSII to cytochrome b6f to PSI. (wikipedia.org)
  • oxidation
  • Monooxygenase uses oxygen to catalyze many oxidation reactions in the body. (wikipedia.org)
  • Yields of these reactions are generally moderate, particularly in the intermolecular case, but tandem intramolecular radical cyclizations initiated by Mn(III) oxidation may generate complex carbocyclic frameworks. (wikipedia.org)
  • 1) The mechanism of manganese(III)-mediated radical reactions begins with the single-electron oxidation of a carbonyl compound to an α-oxoalkyl radical. (wikipedia.org)
  • The fate of 2 is primarily determined by reaction conditions-in the presence of copper(II) acetate, this intermediate undergoes further oxidation to a carbocation and may eliminate to form β,γ-unsaturated ketone 4. (wikipedia.org)
  • proceeds
  • Mathematically, the rate ligand dissociation can increase when the reaction proceeds from one spin state to another, although it must be noted that this effect is often small in comparison with other factors such as sterics around the metal center. (wikipedia.org)
  • Recently, singlet oxygen has been found to be a source of biologically-produced ozone: This reaction proceeds through an unusual compound dihydrogen trioxide, also known as trioxidane, (HOOOH), which is an antibody-catalyzed product of singlet oxygen and water. (wikipedia.org)
  • The halogenation is a typical α-substitution reaction that proceeds by acid catalyzed formation of an enol intermediate. (wikipedia.org)
  • molecule
  • When a chlorophyll a molecule within the reaction center of PSII absorbs a photon, an electron in this molecule attains a higher energy level. (wikipedia.org)
  • If a special pigment molecule in a photosynthetic reaction center absorbs a photon, an electron in this pigment attains the excited state and then is transferred to another molecule in the reaction center. (wikipedia.org)
  • In normal circumstances, the electron should return to the ground state, but, because the reaction center is arranged so that a suitable electron acceptor is nearby, the excited electron can move from the initial molecule to the acceptor. (wikipedia.org)
  • intramolecular
  • The cyclization of ω-epoxy-1-nitriles provides an interesting example of how stereoelectronic factors may override steric factors in intramolecular substitution reactions. (wikipedia.org)
  • electron trans
  • These reactions are closely coupled to the thylakoid electron transport chain as reducing power provided by NADPH produced in the photosystem I is actively needed. (wikipedia.org)
  • species
  • RERs could be derived based either on the species, or on the stoichiometrically independent reactions of a parallel system. (wikipedia.org)
  • The simplified version of this reaction is: C 6H 12O 6 + 6O 2 → 6CO 2 + 6H 2O + 2880 kJ/mol Reactive oxygen species are dangerous by-products that sometimes result from the use of oxygen in organisms. (wikipedia.org)
  • catalyze
  • Since the discovery that copper(I) halides catalyze the conjugate addition of Grignard reagents in 1941, organocopper reagents have emerged as weakly basic, nucleophilic reagents for substitution and addition reactions. (wikipedia.org)
  • yields
  • A variety of substitution patterns may be employed for this transformation, and yields are generally higher than intermolecular coupling reactions. (wikipedia.org)
  • When an alkene reacts with an electrophile, such as HCl, initial addition of H+ gives an intermediate cation and subsequent reaction with Cl− yields an addition product. (wikipedia.org)
  • Reaction on oxygen yields an enol derivative, while reaction on carbon yields an α-substituted carbonyl compound. (wikipedia.org)
  • The use of Li2CuCl4 rather than simple copper(I) halide salts (CuX) improves yields of these coupling reactions substantially. (wikipedia.org)
  • Enzymes
  • The enzymes in the Calvin cycle are functionally equivalent to most enzymes used in other metabolic pathways such as gluconeogenesis and the pentose phosphate pathway, but they are found in the chloroplast stroma instead of the cell cytosol, separating the reactions. (wikipedia.org)
  • In other studies, D.P. Agarwal and colleagues associated race-based variations in the activity alcohol-metabolizing enzymes with the occurrence of alcohol flush reactions to alcohol and alcoholic beverages in certain Asian populations. (wikipedia.org)
  • This early work is the basis for further studies that have defined not only many alcohol-induced flush reactions but also many alcohol-induced respiratory reactions as due to racially associated genetic differences in alcohol-metabolizing enzymes. (wikipedia.org)
  • conjugate
  • Organocopper reagents are now commonly used in organic synthesis as mild, selective nucleophiles for substitution and conjugate addition reactions. (wikipedia.org)
  • In conjunction with Lewis acidic additives such as boron trifluoride etherate, these reagents are used for conjugate addition reactions. (wikipedia.org)
  • allergens
  • Alcohol-induced respiratory reactions, also termed alcohol-induced asthma and alcohol-induced respiratory symptoms, are increasingly recognized as a pathological bronchoconstriction response to the consumption of alcohol that afflicts many people with a "classical" form of asthma, the airway constriction disease evoked by the inhalation of allergens. (wikipedia.org)
  • The study suggested that these reactions were induced by non-alcoholic allergens that were contained in or contaminated the beverages. (wikipedia.org)
  • substrates
  • 2) Arylation of nitrile anions is also possible and can take place through different mechanisms depending on the substrates and reaction conditions. (wikipedia.org)
  • severe
  • Most of the time the reactions are bothersome, but in some cases they can be life-threatening and severe. (medicinenet.com)
  • If you develop a reaction to hair dye, even just a mild one, you should stop using products containing PPD altogether, as there's a risk you could develop a more severe reaction in the future. (www.nhs.uk)
  • SNIDR are most commonly skin reactions that may be relatively mild moderately severe such as maculopapular rash, fixed drug eruptions, photosensitivity reactions, delayed urticaria, and contact dermatitis or extremely severe such as the DRESS syndrome, acute generalized exanthematous pustulosis, the Stevens-Johnson syndrome, and toxic epidermal necrolysis (also termed Lyell's syndrome). (wikipedia.org)
  • The severity of the reaction whilst under anaesthesia is due to the fact that the anaesthetist is only made aware of the allergy when it is severe enough to compromise the cardiovascular system and the respiratory system. (wikipedia.org)
  • synthetic
  • Organic Reactions is a comprehensive reference work that contains authoritative, critical reviews of many important synthetic reactions. (wikipedia.org)
  • The aim of Organic Reactions since its initial publication in 1942 has been to assist organic chemists in the design of new experiments by providing "critical discussions of the more important synthetic reactions. (wikipedia.org)
  • The decision to undertake the preparation and presentation of "critical discussions of the more important (synthetic) reactions" was made at a meeting of the editors of Organic Syntheses and representatives of John Wiley & Sons during the Eighth National Organic Chemistry Symposium at St. Louis in December 1939. (wikipedia.org)
  • however, strongly basic conditions are usually required, which can limit the synthetic usefulness of the reaction. (wikipedia.org)
  • NADPH
  • In the first stage, light-dependent reactions capture the energy of light and use it to make the energy-storage and transport molecules ATP and NADPH. (wikipedia.org)
  • The sum of reactions in the Calvin cycle is the following: 3 CO 2 + 6 NADPH + 6 H+ + 9 ATP → glyceraldehyde-3-phosphate (G3P) + 6 NADP+ + 9 ADP + 3 H 2O + 8 Pi (Pi = inorganic phosphate) Hexose (six-carbon) sugars are not a product of the Calvin cycle. (wikipedia.org)
  • Cyclic phosphorylation is important to create ATP and maintain NADPH in the right proportion for the light-independent reactions. (wikipedia.org)
  • carbon
  • 1) Reductive desulfonylation reactions lead to the replacement of a carbon-sulfur bond in the sulfonyl group with a carbon-hydrogen bond. (wikipedia.org)
  • There are three phases to the light-independent reactions, collectively called the Calvin cycle: carbon fixation, reduction reactions, and ribulose 1,5-bisphosphate (RuBP) regeneration. (wikipedia.org)
  • This set of reactions is also called carbon fixation. (wikipedia.org)
  • The three steps involved are: The enzyme RuBisCO catalyses the carboxylation of ribulose-1,5-bisphosphate, RuBP, a 5-carbon compound, by carbon dioxide (a total of 6 carbons) in a two-step reaction. (wikipedia.org)
  • organic chemistry
  • This combination of critical discussion and thorough coverage is responsible for the leading position this series occupies for scientists interested in the reactions of organic chemistry. (wikipedia.org)
  • chemistry
  • In chemistry, the selection rule (also known as the transition rule) formally restrict certain reactions, known as spin-forbidden reactions, from occurring due to a required change between two differing quantum states. (wikipedia.org)
  • processes
  • concentrations of the nitrile anion must be high to mitigate processes involving self-condensation, such as the Thorpe-Ziegler reaction. (wikipedia.org)
  • Zinc
  • 10. Single-Replacement Reactions FeCl2 + Cu MgBr2 + Cl2 "Magic blue-earth" Zinc in nitric acid 2 A + BC AC + B General Form Zn(NO3)2 + H2 Can Fe replace Cu? (slideshare.net)
  • double bonds
  • Nitrile anions can also be involved in Michael-type additions to activated double bonds and vinylation reactions with a limited number of polarized, unhindered acetylene derivatives. (wikipedia.org)