Natural Electron ACCEPTORS Nicotinamide Adenine Dinucleotide Phosphate (NADP) used in photosynthesis in chloroplasts NADP + + 2H + + 2e - NADPH + H + Ferredoxin the most difficult to reduce (and most easily oxidised) Cytochromes Conjugate proteins which contain a haem group. The iron atom undergoes redox reactions Fe 3+ + e - Fe 2+ NB The iron atom in the haem group of haemoglobin does not go through a redox reaction Haemoglobin is oxygenated or deoxygenated Reduction Oxidation Reduction Oxidation © 2010 Paul Billiet ODWSODWS
Detection of different oxidation states of individual manganese porphyrins during their reaction with oxygen at a solid/liquid ...
for different oxidation states of the same element in X-ray photoelectron spectroscopy measurements, should the full width half maximum (FWHM) value be the same for all? Is this a parameter to fix in this case for the fitting ...
N,N-Dialkylhydroxylamines where the alkyl groups are of 10 to 30 carbon atoms are prepared by an improved process involving the direct oxidation of the corresponding N,N-dialkylamines with aqueous hydrogen peroxide in a lower alkanol solvent in the absence of a catalyst or a sequestering agent. The improved process prevents the problem of over-oxidation and gives the desired N,N-dialkylhydroxylamine in high yield and purity. The N,N-dialkylhydroxylamines are effective stabilizers for polymer compositions particularly as process stabilizers for polyolefins.
From the stock market to politics, keeping gains and losses straight these days can be confusing. Scientific gains and losses can be equally overwhelming. Thankfully, in Mondays Scientific Spotlight Session on Redox Biology in Thrombosis, the pathways involved in electron losses and gains and their effect on platelet biology were highlighted by two thought leaders.. Reactive oxygen species (ROS), a type of unstable molecule, are a natural byproduct of aerobic metabolism involved in endogenous signaling. A buildup of ROS is associated with oxidative stress and is implicated in disease states, including atherosclerosis, diabetes, neurodegeneration, and aging. ROS and redox biology have received significant attention in vascular biology; however, there has previously been little focus on ROS production by, and influences on, platelet function. Co-Chair Craig Morrell, DVM, PhD, explored the intersection of platelets and thrombosis through investigating the role of ROS in platelet function. Dr. ...
... is a forum for novel research, methods and review articles in redox biology in the areas of both health and disease. Acceptable paper...
The possibility of employing cellular automata (CA) to model photo-induced oxidation processes in molecularly doped polymers is explored. It is demonstrated that the oxidation dynamics generated using CA models exhibit stretched-exponential behavior. This dynamical characteristic is in general agreement with an alternative analysis conducted using standard rate equations provided the molecular doping levels are sufficiently low to prohibit the presence of safe-sites which are impenetrable to dissolved oxygen. The CA models therefore offer the advantage of exploring the effect of dopant agglomeration which is difficult to assess from standard rate equation solutions. The influence of UV-induced bleaching or darkening upon the resulting oxidation dynamics may also be easily incorporated into the CA models and these optical effects are investigated for various photo-oxidation product scenarios. Output from the CA models is evaluated for experimental photo-oxidation data obtained from a series of hydrazone
... reactions chemically convert hazardous contaminants to less toxic compounds that are less mobile and/or inert. Redox reactions involve the transfer of electrons from one compound to another. One compound is oxidized (loses electrons) and one is reduced (gains electrons). Oxidizing agents most commonly used for treatment of hazardous contaminants are ozone, hydrogen peroxide, hypochlorite, chlorine, and chlorine dioxide. The reducing agents most commonly used for treatment of hazardous waste are ferrous sulfate, sodium bisulfite, and sodium hydrosulfite. Experimental systems have been used to oxidize trichloroethylene (TCE) and perchloroethylene (PCE ...
The present invention relates to an integrated process and apparatus for supplying at least a portion of, or substantially all, or all of the reducing gas feedstock to a reduction reactor, such as a reactor for the direct reduction of iron, wherein the reducing gas contacts a feed material at a mean operating gas pressure and effects reduction of the feed material to provide a reduced product. The integrated process includes the production of a hydrogen-rich gas by the partial oxidation of a hydrocarbonaceous feedstock to produce a hydrogen-rich gas, which can also be referred to as a synthesis gas or syngas. The synthesis gas is at a pressure substantially greater than the mean operating gas pressure in the reduction reactor. The synthesis gas is expanded to lower its pressure to substantially the mean operating gas pressure in the DRI reduction reactor to thereby form the reducing gas feedstock at the pressure conditions used for the DRI reaction. The lower pressure reducing gas mixture generated by
Under normal physiological conditions, ROS levels are low and ROS detoxification is easily managed by intrinsic antioxidant defence systems. In this context, ROS benefit neuronal health because of their central role in redox signalling. Redox-dependent signalling pathways are made up of redox-sensitive proteins that can undergo reversible oxidation or reduction reactions. The function of redox-sensitive proteins change depending on whether a protein is in its oxidized or reduced state. Thus ROS-RNS interaction influences protein signalling capacity in a redox-dependent manner. ROS and RNS play a key role in a variety of biologically important neural pathways including LTP (long-term potentiation), synaptic plasticity, neurogenesis, neuronal differentiation, apoptosis and the establishment of neuroprotective preconditioning [3,4]. Cellular signalling is also influenced by redox status at the transcriptional level, as numerous transcription factors are redox-sensitive, including NF-κB (nuclear ...
Im trying to increase my thickness uniformity in SiO2 deposition for a dry, high temperature oxidation process. My wafer profile is thin in the middle and thic
Despite recent advances in the field of vascular redox signalling in hypertension, it still remains unclear exactly how ROS cause vascular injury. We hypothesise that regulation of redox-sensitive protein tyrosine phosphatases (PTP) through oxidative modification, is impaired in hypertension. VSMC normotensive (NT) and hypertensive (HT) individuals were stimulated with AngII (10-7 M) and ET-1 (10-7 M). Irreversible oxidation of proteins and PTPs was assessed by oxyblot. Differential gel electrophoresis (DiGE) and CyDye thiol labelling were employed for screening of reversibly oxidised proteome. Irreversible protein oxidation was not affected by AngII or ET-1 in VSMCs from NT and HT subjects. Proteomic data, filtered for FC ,2, detected 2051 spots with 1899 (92.5%) being equally oxidised between NT and HT. In addition, oxidation of 57 (2.9%) spots was increased, while 95 (4.6%) were decreased in HT. Candidate proteins exhibiting consistent changes across three experimental replicates included ...
Purchase Thiol Redox Transitions in Cell Signaling, Part A, Volume 473 - 1st Edition. Print Book & E-Book. ISBN 9780123813459, 9780123813466
Our earlier experimental study has shown that exhaust unburnt hydrocarbon emissions from spark-ignition engines can be reduced effectively by using in-cylinder catalysts on the surface of the piston top-land crevice. In order to improve the understanding of the process and mechanism by means of which unburnt hydrocarbon emissions are reduced, a phenomenological mathematical model was developed for catalytic oxidation processes in the piston-ring-pack crevice.This paper describes in details the modelling of the processes of the gas flow, mass diffusion and reaction kinetics in the crevices. The flow in the crevices is assumed to be isothermal and at the temperature of the piston crown surface. The overall rate of reaction is calculated using expressions for mass diffusion for laminar flows in channels and a first-order Arrhenius-type expression for catalytic reaction kinetics of hydrocarbon oxidation over platinum.The model is capable of describing the time-dependent behaviour of the gas flow and ...
The Earths original atmosphere held very little oxygen. This began to change around 2.4 billion years ago when oxygen levels increased dramatically during what scientists call the "Great Oxidation Event." The cause of this event has puzzled scientists, but researchers writing in Nature have found indications in ancient sedimentary rocks that it may have been linked to a drop in the level of dissolved nickel in seawater.. "The Great Oxidation Event is what irreversibly changed surface environments on Earth and ultimately made advanced life possible," says research team member Dominic Papineau of the Carnegie Institutions Geophysical Laboratory. "It was a major turning point in the evolution of our planet, and we are getting closer to understanding how it occurred.". The researchers, led by Kurt Konhauser of the University of Alberta in Edmonton, analyzed the trace element composition of sedimentary rocks known as banded-iron formations, or BIFs, from dozens of different localities around the ...
This thesis deals mainly with two oxidation reactions: water oxidation and aerobic oxidation, both of which have been applied in a biomimetic fashion. In the former reaction molecular oxygen is generated whereas in the latter it was used as terminal oxidant in oxidation reactions.. The first part of this thesis describes the synthesis of different ruthenium and manganese complexes that could potentially act as catalysts for water oxidation. This part includes a discussion of the stability and reactivity of a new manganese(III) amide-type complex, that has been used as a catalyst for both epoxidation of stilbene and alcohol oxidation.. The second part of this thesis discusses the synthesis of two new hybrid catalysts consisting of hydroquinone linked cobalt(II) salophen and cobalt(II) salmdpt, which have been used as oxygen-activating catalysts in aerobic oxidation reactions. The former catalyst was applied to the Pd-catalyzed reactions such as 1,4-diacetoxylation of cyclohexadiene whereas the ...
The reinvestigation of the kinetics of myeloperoxidase (MPO) activity with the use of NADPH as a probe has allowed us to determine the effects of H2O2, Cl- ion and pH on the MPO-dependent production of HOCl. The chlorination rate of NADPH did not depend on NADPH concentration and was entirely related to the rate of production of HOCl by MPO. The overall oxidation of NADPH occurred similarly in the absence of O2 and was insensitive to scavengers of the superoxide radical anion. Experiments performed on the direct oxidation of NADPH by MPO in the presence and the absence of H2O2 showed that neither the rate nor the stoichiometry of the reaction could interfere in the NADPH oxidation process involved in the steady-state chlorination cycle. The oxidation of NADPH was characterized by a decrease in the A339 of the reduced nicotinamide with the concomitant appearance of a new chomophore with absorbance maximum at 274 nm, characterized by isosbestic points at 300 and 238 nm. The reaction product did ...
Decreased Complete Oxidation Capacity of Fatty Acid in the Liver of Ketotic Cowsa - Dairy Cow;Ketosis, Liver;Fatty Acid Oxidation;
One way to quantify whether a substance is a strong oxidizing agent or a strong reducing agent is to use the oxidation-reduction potential or redox potential. Strong reducing agents can be said to have a high electron-transfer potential. Strong oxidizing agents have low electron-transfer potential. Oxidizing and reducing agents occur as couples, with a strong reducing agent coupled with a weak oxidizing agent and vice versa. Since these processes involve the transfer of electrons, the measurement of the resulting charge separation can be quantified in voltage measured between the couple and a standard hydrogen half-cell with 1 molar hydrogen and 1 atmosphere of hydrogen pressure on it. The redox potential of the hydrogen is zero at pH=0, but for tabulations a pH=7 is used for the hydrogen and under those conditions its redox potential is -0.421 volts. As a useful reference, the redox potentials of couples that commonly occur in biochemistry can give insight into their roles in biological energy ...
Get this from a library! Transformations of halogenated hydrocarbons : hydrolysis and redox processes. [N Lee Wolfe; Peter M Jeffers; Environmental Research Laboratory (Athens, Ga.)]
Understanding how oxidation of proteins leads to reversible alterations in protein function is relevant for proteins involved in cellular signaling processes, including protein tyrosine phosphatases (PTPs). Two groups, Salmeen et al. and van Montfort et al., show that PTP1B is reversibly oxidized by such chemicals as hydrogen peroxide or 2-phenyl-isoxazalidine-3,5-dione and forms a previously uncharacterized sulfenyl-amide because of oxidation of the catalytic site cysteine. Both groups analyzed the crystal structure of PTP1B after exposure to oxidizing conditions and identified the formation of the sulfenyl-amide, which caused large changes in the conformation of the active site. Salmeen et al. reported inhibition of substrate binding in the peroxide-exposed PTP1B, consistent with the structural changes blocking substrate recognition. This novel intermediate may effectively protect PTP1B from irreversible inactivation that would result from the formation of sulfinic or sulfonic acids.. A. ...
Cysteines play important roles in the biochemistry of many proteins. The high reactivity, redox properties, and ability of the free thiol group to coordinate metal ions designate cysteines as the amino acids of choice to form key catalytic components of many enzymes. Also, cysteines readily react with reactive oxygen and nitrogen species to form reversible oxidative thiol modifications. Over the last few years, an increasing number of proteins have been identified that use redox-mediated thiol modifications to modulate their function, activity, or localization. These redox-regulated proteins are central players in numerous important cellular processes. First aim of this study was to discover nitric oxide (NO) sensitive proteins in E. coli, whose redox-mediated functional changes might explain the physiological alterations observed in E. coli cells suffering from NO-stress. To identify E. coli proteins that undergo reversible thiol modifications upon NO-treatment in vivo, I applied a differential ...
Cancer can be viewed as a state in which the balance between cell proliferation and cell death aberrantly favors the former. We and others have discovered that the intracellular redox environment exerts a profound influence on the normal cellular processes that regulate the balance between proliferation and cell death, including DNA synthesis, enzyme activation, cell cycle progression, proliferation, differentiation, and apoptosis. In fact, it could be argued that redox homeostasis is central to the governance of cell fate. Unfortunately, molecular mechanisms mediating redox sensitivity and regulation within cells are still poorly defined. Current pharmacological methods to alter intracellular redox state are limited by (i) their inability to operate independent of global biochemical alterations and cellular toxicity, and (ii) the required significant manipulation of culture conditions that perturb intracellular homeostasis. Our genetic constructs overcome these limitations as they enable ...
Apoptosis is a regulated "programme" by which cells are induced to die in a manner which does not result in pathological inflammatory reactions, and involves dismantling of the cell into membrane-bound fragments that are removed by phagocytosis. This process is induced in order to remodel tissues and maintain homeostasis in cell numbers. Apoptosis may be induced via many pathways, many of which are redox-regulated, and is dysregulated in cancer cells, mainly due to mutational inactivation of certain pathways. Cancer cells also have a non-linear response to redox imbalance, a potentially exploitable characteristic for the therapeutic selective induction of apoptosis in cancer cells in mixed cell populations. Model cell culture systems are required for the selective toxicity testing of anti-cancer drugs, many of which work by inducing redox stress. In the current study, hydrogen peroxide was selected as the redox stress-inducing agent, and the test cells were an immortal, non-invasive breast ...
This process pertains to a achieving high on-stream time and maintaining the temperature and composition of the raw effluent gas stream from a partial oxidation gas generator being fed simultaneously with a stream of gaseous fuel and separate stream of liquid hydrocarbonaceous fuel. Two parallel oxygen streams equipped with flow transmitters and control valves are used to supply the oxygen associated with two separate and different fuel streams. Each stream of oxygen is controlled by an O2 /fuel ratio control so that if the flow rate of either stream of fuel or its related oxygen stream changes, the oxygen/carbon atomic ratio of the remaining O2 and fuel stream in the gasifier is maintained at a desired value. Further, if either fuel flow is stopped, its associated O2 flow will stop, but the remaining fuel stream and its associated O2 stream will continue to flow at the same rate with no change in the oxygen/fuel weight ratio. Complete shut down of the unit is thereby avoided. The quick raising of
Oxidation-reduction (redox) reactions are among the most important and interesting chemical reactions that occur in aquatic environmental systems, which include soils, sediments, aquifers, rivers, lakes, estuaries, water treatment and distribution systems, etc. This volume provides a comprehensive overview of aquatic redox chemistry through chapters contributed by many of the leading investigators in the field.
The low-temperature reaction of [CrCl3(thf)3] with LiC6H3Cl2-2,6 yields the organochromium(III) compound [Li(thf)4][CrIII(C6H3Cl2-2,6)4] (1) in 48% yield. The homoleptic, anionic species [CrIII(C6H3Cl2-2,6)4]− is electrochemically related to the neutral one [CrIV(C6H3Cl2-2,6)4] (2) through a reversible one-electron exchange process (E1/2 = 0.16 V, ΔEp = 0.09 V, ipa/ipc = 1.18). Compound 2 was isolated in 74% yield by chemical oxidation of 1 with [N(C6H4Br-4)3][SbCl6]. Attempts to prepare the salt [NBu4][CrIII(C6Cl5)4] (4) by direct arylation of [CrCl3(thf)3] with LiC6Cl5 in the presence of [NBu4]Br gave the organochromium(II) salt [NBu4]2[CrII(C6Cl5)4] (3) instead, as the result of a reduction process. The salt [NBu4][CrIII(C6Cl5)4] (4) was cleanly prepared by comproportionation of 3 and [CrIV(C6Cl5)4]. The reaction of [MoCl4(dme)] with LiC6Cl5 in Et2O solution proceeded with oxidation of the metal center to give the paramagnetic (S = 1/2), five-coordinate salt [Li(thf)4][MoVO(C6Cl5)4] (5). ...
To understand the benefits of antioxidants its important to know what an antioxidant does. An antioxidant is anything that can slow down or stop the oxidation process once it has started. The oxidation process is a chemical reaction that involves ...
Chemically, oxidation is defined as the removal of electrons and reduction as the gain of electrons. Thus, oxidation of a molecule (the electron donor) is always accompanied by reduction of a second molecule (the electron acceptor). This principle of oxidation-reduction applies equally to biochemical systems and is an important concept underlying understanding of the nature of biologic oxidation. Note that many biologic oxidations can take place without the participation of molecular oxygen, for example, dehydrogenations. The life of higher animals is absolutely dependent upon a supply of oxygen for respiration, the process by which cells derive energy in the form of ATP from the controlled reaction of hydrogen with oxygen to form water. In addition, molecular oxygen is incorporated into a variety of substrates by enzymes designated as oxygenases; many drugs, pollutants, and chemical carcinogens (xenobiotics) are metabolized by enzymes of this class, known as the cytochrome P450 system. ...
Photosynthesis is a redox process both OXIDATION AND REDUCTION. Oxidation and reduction go hand in hand. Cellular respiration is a redox process too, both oxidation and reduction. so in Photosynthesis carbon dioxide (CO2) is reduced to form sugar (C6H12O6) while in respiration, sugar (C6H12O6) is oxidized to form carbon dioxide (CO2). ;) (Campbell, Biology sixth edition, pag, 110, Figure 7.4A and Figure 7.4B) Vete ...
This is an introduction to oxidation-reduction reactions, also known as redox reactions. Learn what redox reactions are and get examples.
Chemistry Assignment Help, What are metal oxides and oxoanions?, The elements of first transition series from variety of oxides of different oxidation states having general formulae MO, M 2 O 3 , M 3 O 6 , MO 2 , MO 3 . These oxides are generally formed by heating the metal with oxygen at high temperature. The
The befitting capping capabilities of AsO43− provide a stable Cu2O nanocatalyst from a galvanic reaction between a Cu(ii) precursor salt and As(0) nanoparticles. This stable Cu2O hydrosol appears to be a suitable catalyst for the one-electron transfer reversible redox reaction between Eosin Y and NaBH4. The
 These reactions are called oxidation reduction reactions. The electrons that are lost or gained are high energy electrons.  Example: if one atom is oxidized or loses an electron, that atom becomes partially charged(an ion) Atom X(oxidized) Ion X + +e _ The electron is picked up by another positive ion and becomes an atom Ion Y + + e _ Atom Y
The NiAT-M and NiIT-M complexes are reversibly interconverted by a 2H+-2e− reaction;66 therefore, interconversion of NiAT and NiIT was examined. The conversion of NiAT to NiIT was performed by treating NiAT suspended in water with a base (NEt3) followed by adding ferrocenium tetrafluoroborate as an oxidizing agent. The conversion was reversed by the addition of acetic acid followed by the reducing agent, decamethylcobaltocene. This was confirmed directly by monitoring the characteristic N-H stretching signals in the IR spectra (Fig. S8†). The double N-H stretching peaks changed to a single peak upon the chemical oxidation of NiAT, indicating the formation of NiIT, and the double peaks reappeared upon the chemical reduction of NiIT, forming NiAT. Overall, these results demonstrate that NiAT and NiIT are chemically interconvertible without decomposition or a change in shape.. We previously found that pelletized NiIT showed a semiconducting nature with the activation energy of 41 meV and the ...
Cytochrome oxidase, the terminal oxidase of the electron transport chain, is classically known to be a membrane bound protein of a molecular weight close to 200,000 Daltons which contains two copper atoms (Cu(,D) and Cu(,U)) and two heme groups, cytochromes a and a(,3). The enzyme is found in aerobic organisms where its function is to catalyze the reduction of oxygen to water and to promote oxidative phosphorylation to satisfy the energy requirements of the cell. The purpose of this thesis is to define the oxidative-reductive (redox) intermediates of the enzyme. Physico-chemical methods are used to obtain information on the structural and valence characteristics, the electronic states, and the redox properties of the four metals involved in catalysis. Methods such as magnetic susceptibility, electronic absorption spectroscopy, electron paramagnetic resonance (EPR), and magnetic circular dichroism (MCD) have been used to monitor several types of redox intermediates. Redox titrations have been ...
This study addresses the fundamentals of an important degradation pathway of storing protein pharmaceuticals in an aqueous formulation, oxidation of methionine residues by peroxides. First, a mechanism by which methionine residues are oxidized is identified via ab initio calculations. The major difference of this new mechanism to previous ones is the role of solvent molecules in the oxidation process. Previously proposed mechanisms suggested that solvent molecules facilitate the transfer of hydrogen associated with the oxidation reaction, but the estimated activation energies and pH dependence of oxidation rates derived from this mechanism rates do not agree with experimental observations. In our proposed mechanism, however, water molecules stabilize the charge separation in the transition-state complex through specific interaction such as hydrogen bonding. This mechanism satisfies all experimental studies on the oxidation of organic sulfides by peroxides. A correct picture of instability ...
Photosynthesis is a redox process both OXIDATION AND REDUCTION. Oxidation and reduction go hand in hand. Cellular respiration is a redox process too, both oxidation and reduction. so in Photosynthesis carbon dioxide (CO2) is reduced to form sugar (C6H12O6) while in respiration, sugar (C6H12O6) is oxidized to form carbon dioxide (CO2). ;) (Campbell, Biology sixth edition, pag, 110, Figure 7.4A and Figure 7.4B) Vete ...
An apparatus and method for withdrawing gaseous decomposition products from a refuse dump. Disposed at various locations in the refuse are gas collection mechanisms, such as gas wells, drainage systems, etc., each of which is connected via a gas withdrawal line with a collector, from which the gas is withdrawn for further utilization. Disposed in each gas withdrawal line is a sensor and a regulatable shutoff device. The sensor transmits the content of a characteristic constituent of the gas flow in a given gas withdrawal line to a measuring and control unit, which monitors the gas flow volume as a function of a comparison of the sensor signals with preset threshold values. If the sensors indicate that the content of the characteristic constituent of the gas flow exceeds or drops below the preset threshold values, the measuring and control unit opens or closes the associated shutoff device by an appropriate amount.
Shi, F., Tse, M. K. and Beller, M. (2007), A Novel Environmentally Benign Method for the Selective Oxidation of Alcohols to Aldehydes and Ketones. Chem. Asian J., 2: 411-415. doi: 10.1002/asia.200600383 ...
Now that we balanced the electrons, only atomic balance is left to complete this half redox reaction. Reaction proceeds in acidic medium, so we must include H+ on the left side; as oxygen is no longer present in the right side, and we put H+, you can easily conclude that water will be present on the right side ...
Meaning of the word Oxidation-reduction Indicator with word definition and statistical analyze of the Oxidation-reduction Indicator word as pure text.
The fermentation of sugar (C6H12O6) to form ethanol (C2H5OH) and carbon dioxide (CO2) occurs according to the following equation: C6H12O6(aq) ¡ú 2 C2H5OH(aq) + 2 CO2(g) kJ mol¨C1 ¦¤Hf (C6H12O6(s)) is ¨C1275 ¦¤Hf (C2H5OH(l ...
Blast furnace (B/F) operations; B/F irregularities and remedial measures, B/F refractories and causes of failure, modern trends in (B/F) technology overview of direct reduction processes, electric smelting; production of DRI (HBI/Sponge iron ...
The oxidation of organic molecules mediated by metal surfaces is a subject of immense importance. Either complete oxidation to water and carbon dioxide or partial and selective oxidation to valuable...
The electron hopping in SWCNT-mediated redox reaction of anthraquinonnyl (AQH2-) and 4-arylhydroxyl amine (4AHA-) groups is systematically studied by DFT for the first time. The spin-unrestricted DFT calculations were performed with generalized gradient approximation (GGA) as in the Perdew-Burke-Ernzerhof (PBE) functional and an all-electron double numerical basis set with polarized function (DNP). The SWCNT-mediated reaction was proposed earlier to be more favorable than the tunneling process through reagents because the electron transfer distance is shorter. In this work, we then investigate the reaction mechanism of electron hopping involved with the reversible oxidation and irreversible reduction reactions through AQH2-SWCNT-4AHA (substrate), [AQH-SWCNT-4AHA]1- (intermediate-1), [AQ-SWCNT-4AHA]2- (intermediate-2), [AQ-SWCNT-Ph-NH]1- (intermediate-3), and AQ-SWCNT-4AA (product) (AQ = anthraquinonyl, 4AHA = 4-arylhydroxyl amine, 4AA = 4-arylamine, SWCNT = (8,0) zigzag SWCNT). It was found that
Imagine for a moment that you are a car. Now imagine that you have 100 trillion horsepower. To produce that horsepower, or energy, you produce a lot of exhaust from burning fuel. The horsepower is the equivalent of the power produced in the energy producing "mitochondria" in your cells and the exhaust is the "oxidation" that happens when the fuel you eat is burned with oxygen in the mitochondria. Since oxidation can be harmful, we have a clever way of counteracting oxidation with anti-oxidants.. Now, imagine that you put diluted or contaminated fuel into your car or put the wrong kind of oil in the engine. The engine would become very clogged or "inflamed". If you dont put in enough anti-oxidants, the engine might become oxidized, just like a piece of metal that has changed color. That would contribute to sluggish performance or energy production. You could think of it as altered metabolism.. It is turning out that the mitochondria are important in a wide variety of body processes and are ...
Oxidation and reduction reactions go hand in hand, which is why they are also called redox reactions. Acids and bases may be thought of as reactions involving hydrogen, or protons, while redox reactions tend to be concerned with electron gain and loss. ...
The mission of the Messens lab is to establish a detailed functional and structural view on the mode of action of the proteins involved in surviving oxidative stress by exploring the electron transfer redox pathways that tightly control sulfur oxygen signaling through reversible switch mechanisms on cysteines and methionines in pathogenic Actinomycetes and plants. Several oxidoreductase proteins, which successively pass on electrons via complex intra- and intermolecular cascades using thiol-disulfide chemistry, are involved. We want to understand how redox-regulated checkpoints are embedded into a variety of metabolic pathways and how cells rapidly switch between distinct catabolic or anabolic processes, protect particularly vulnerable intermediates, and activate survival pathways in response to oxidative stress. Ultimately, we want to translate our knowledge back to the cell or the crop, so that we can cure infectious diseases or design crops that survive extreme conditions.. ...
One of the most characteristic features of n-acetylcysteine is the presence of a thiol group, which is extremely important for human metabolism and its proper functioning. This fraction is involved in the production of specific connections, which are professionally referred to as "disulphide bridges". These bridges are extremely important for protein molecules, including muscle proteins, due to their tertiary structure. This, on the other hand, affects the stabilization of protein structure, increasing their resistance to degradation resulting, for example, from too high temperature, harmful oxidation processes or adverse catabolic reactions.. However, -amino-ß-thiolopropionic acid is primarily recognized as a potent detoxification compound. The purifying properties of l-cysteine is demonstrated by a number of processes in which it takes a significant part. One of the examples is its necessary participation in the production of glutathione, a substance considered to be the basic antioxidant of ...
A two-stage combustion is one of the Mitsubishi GDI™ technologies for a quick catalyst warm-up on a cold-start. However, when the combustion is continued for a long time, an increase in the fuel consumption is a considerable problem. To solve the problem, a stratified slight-lean combustion is newly introduced for utilization of catalysis. The stratified mixture with slightly lean overall air-fuel ratio is prepared by the late stage injection during the compression stroke. By optimizing an interval between the injection and the spark timing, the combustion simultaneously supplies substantial CO and surplus O2 to a catalyst while avoiding the soot generation and the fouling of a spark plug. The CO oxidation on the catalyst is utilized to reduce the cold-start emissions. Immediately after the cold-start, the catalyst is preheated for the minimum time to start the CO oxidation by using the two-stage combustion. Following that, the stratified slight-lean combustion is performed ...
A two-stage combustion is one of the Mitsubishi GDI™ technologies for a quick catalyst warm-up on a cold-start. However, when the combustion is continued for a long time, an increase in the fuel consumption is a considerable problem. To solve the problem, a stratified slight-lean combustion is newly introduced for utilization of catalysis. The stratified mixture with slightly lean overall air-fuel ratio is prepared by the late stage injection during the compression stroke. By optimizing an interval between the injection and the spark timing, the combustion simultaneously supplies substantial CO and surplus O2 to a catalyst while avoiding the soot generation and the fouling of a spark plug. The CO oxidation on the catalyst is utilized to reduce the cold-start emissions. Immediately after the cold-start, the catalyst is preheated for the minimum time to start the CO oxidation by using the two-stage combustion. Following that, the stratified slight-lean combustion is performed ...
Roll the filling away from you once, so that the filling is covered. Spray with nonstick cooking spray, and fold edges in (burrito style!). Continue to roll until your spanakopita burrito is finished, and place on baking sheet sprayed with nonstick cooking spray. Repeat process with next three spanakopita rolls.Bake at 400 degrees for 25 minutes, and enjoy! Delicious and filling dinner :). Why: Spinach is extremely high in Vitamin A, which I have discussed in detail in my Sweet Potato and Spinach Risotto post- be sure to read that information! Spinach is also an excellent source of Vitamin E, a powerful antioxidant which neutralizes free radicals in the body that cause damage to transport molecules in the body, the cell membrane, and even causes damage to DNA, RNA, and many proteins. Vitamin E specifically works to stop the oxidation process in those transport molecules and in our cell membranes, When the transport lipoproteins are oxidized (i.e. when LDL is oxidized), plaque forms more readily ...
more redox reactions. II. Redox reactions - P doesnt go through redox reactions itself, but it is influenced by the solubility of Fe, which changes due to its redox state ...
Read Practice Makes Perfect in Chemistry: Oxidation-Reduction by John Parnell with Rakuten Kobo. One of the best ways to succeed in Chemistry is to practice taking real test questions. This volume contains 183 problem...
The Secretary of the United States Air Force has obtained a patent for a method for enhancing the oxidation resistance of substrates fabricated from carbon-carbon and metals and alloys which have a minimal reaction with
Both 3C-SiC and 6H-SiC single-crystal films can be grown on vicinal (0001) 6H-SiC wafers. We have found that oxidation can be a powerful diagnostic process for (1) color mapping the 3C and 6H regions of these films, (2) decorating stacking faults in the films, (3) enhancing the decoration of... mehr ...
World Conference of Science Journalists in London this week, so heres a sneak preview of the July 1 issue of SpectroscopyNOW from the David Bradley segments in celebration. Wish me luck in defending my corner against those who would smite the science writers from our midst…. Iron proteins cast in surprising role - Iron is the most abundant transition metal in the human body. Its intriguing reduction-oxidation properties endow it with the active role as an essential cofactor in countless proteins. Some of these are involved in oxygen transport (haemoglobin in the blood), electron exchange for powering biochemical reactions and energy release (cytochromes), and the control of potentially harmful free radicals.. However, little is known about how the haem group that carries oxygen in blood and is the active centre of several enzymes is transported from where it is made in the cell to its host protein assembly. Now, UV-Vis spectroscopy has helped identify an enzyme that also functions as a haem ...
Chlorine based processes for bleaching paper use redox chemistry that produces a complex mixture of chlorinated products that are hazardous to human health and the environment. This module describes the development and use of tetraamido-macrocyclic ligand activators (TAMLTM) as oxidant activators to reduce the environmental impact of the bleaching process. TAMLTM activators are iron macrocyclic structures that catalyze hydrogen peroxide oxidation reactions important for bleaching paper. The TAMLTM based technology is more efficient and can be used at lower temperatures thus resulting in significant energy savings. The module includes a brief description of the history, chemistry and manufacturing process for paper and is recommended for a descriptive inorganic class. A comparison and evaluation of the two bleaching processes is also included and may be appropriate for an advanced inorganic course describing oxidizing agents or the effect of substituents on organometallic redox reactions. The ...
For a long time, reactive oxygen species have been mostly regarded as unwanted and damaging side-products of cellular metabolism. However, it has become clear that some of these species, in particular hydrogen peroxide (H2O2), play important positive roles as signaling molecules, and thus are essential for organismal health. Oxidative signals are now recognized to trigger adaptive responses and adequate cell fate decisions. The signaling function of H2O2 is based on the reversible oxidative modification of transcription factors and other proteins involved in cell regulation. Our special attention is devoted to the molecular mechanisms by which H2O2 achieves specificity as a signaling molecule. We are investigating signaling pathways by which endogenous H2O2 contributes to metabolic stress adaptation and cytoprotection. Furthermore, we aim to understand how tumor cells take advantage of redox signaling pathways ...
Attendance at quizzes and exams is mandatory. Makeups will be administered only if I deem the reason for the absence to be legitimate and I am made aware of the absence beforehand!! Each documented, unexcused lecture absence beyond the first two will cost you one point from your total. CHEM 22105 CHRONODYNAMICS. Date Topic Text Q/E. 1/10 introduction/radicals 5.2,3,8. 1/12 representative radical chains 7.10, 10.3,4. 1/14 mass spectrometry 12.1-3. 1/17 NMR theory 13.1-3,8,9. Chp 27, lab manual 1/19 chemical shift and coupling 13.10,11,13 1/21 proton NMR problems - Quiz 1. 1/24 carbon NMR 13.4,5. 1/26 physical/spectroscopic properties of alcohols 17.1,2,12 1/28 substitution/elimination rxns of alcohols 17.3,7, 18.3 Quiz 2. 1/31 redox chemistry of alcohols 17.8. 2/2 ethers 18.1,4 2/4 Exam 1 - Exam 1. 2/7 epoxides 18.7,8. 2/9 diene structure 1.6-9, 12, 14.2. 2/11 electrophilic additions to dienes 14.3,4. 2/14 the Diels-Alder rxn (finest in org. chem.) 14.5,6. 2/16 intro to arenes 15.1-3 2/18 ...
Redox processes regulate plant/insect responses but the precise roles of environmental triggers and specific molecular components remain poorly defined. Aphid f...
Cremonini, E., Wang, Z., Bettaieb, A., Adamo, A. M., Daveri, E., Mills, D. A., Kalanetra, K. M., Haj, F., Karakas, S. E. & Oteiza, P. I., Apr 1 2018, In : Redox Biology. 14, p. 588-599 12 p.. Research output: Contribution to journal › Article ...
Jeannette Vasquez Vivar, PhD, is a professor in the Department of Biophysics and associate director of the Redox Biology Program.
Our research focuses on deciphering molecular mechanisms that drive metabolic disease, and using this information to develop targeted therapeutic strategies. Mitochondria are critical hubs for metabolic signalling, and their dysfunction is key in the pathology of metabolic disease. We combine mass spectrometry and targeted pharmacological approaches in vivo to understand how mitochondrial redox metabolism controls physiology in clinically informative mouse models of obesity and diabetes. ...
This paper provides a systems level integration of the molecular events subject to reversible oxidation during IL-4 signal transduction. Code for simulation provided.
Our doctors want to give our patients a cancer free life, that is why they use a lethal combination for cancerous tumors to kill them, using vitamin C and K.
Now add the two half-reactions: 10 I- → 5 I2 + 10 e- 16 H+ + 2 MnO4- + 10 e- → 2 Mn2+ + 8 H2O This yields the following final equation: 10 I- + 10 e- + 16 H+ + 2 MnO4- → 5 I2 + 2 Mn2+ + 10 e- + 8 H2O Get the overall equation by canceling out the electrons and H2O, H+, and OH- that may appear on both sides of the equation: 10 I- + 16 H+ + 2 MnO4- → 5 I2 + 2 Mn2+ + 8 H2 ...
We breakdown what happens to your body during intense exercise and why trying to eliminate cell oxidisation is not recommended.. ...
Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Nanoteknologi och funktionella material. (Nanoteknologi och Funktionella Material) ...
Oxidation numbers are assigned using a strict set of rules. The rules state that each atom in its elemental form has an oxidation number of zero. Another key rule states that ions have oxidation...
JCI - Series Introduction: The expanding network of redox signaling The organization of redox signaling and the use of oxygen to transmit information are proving to be much more complex than one could have originally imagined ... ...
I need help understanding how to solve redox equations. If you could explain this to me in simple terms I would really appreciate it. i have a sample problem and cant even get past it. The problem is: K2CrO4 + Mg + HCl to.
A free platform for explaining your research in plain language, and managing how you communicate around it - so you can understand how best to increase its impact.
生命离不开氧,细胞的氧化还原状态直接调控蛋白质等大分子功能,氧化还原应激是细胞信号转导和效应的重要调控方式,介导衰老、神经退行性疾病、代谢病、肿瘤等许多生理和病理过程。陈畅课题组长期致力于系统揭示细胞内氧化还原生物活性小分子的产生和代谢,发现氧化还原调控的新基因,结合自主构建的特异氧化还原探针和超高分辨成像技术,"绘制"细胞内不同细胞器內源氧化还原状态全景图谱(Redox Map),阐述氧化还原活性小分子与生物大分子的cross ...
Oxidation Reduction Agent directory ☆ Oxidation Reduction Agent manufacturers, suppliers ☆ Oxidation Reduction Agent buyers, importers, wholesalers, distributors
This resource was assembled for the primary purpose of serving the research needs of students and investigators in the field of redox biology. Redox biology is wide-ranging and complex and can present significant challenges to investigators seeking to address research questions in biological systems. Our goal is provide information on the basic principles of redox biology and links to important research resources. For example, a page is devoted to reactive oxygen species highlighting the chemical properties and methods of detection for different reactive oxygen species. In addition, functional and structural information is provided for key redox enzymes/proteins as well as properties of redox metals. Links to various bioinformatics tools are also available which allow researchers to search for selenoproteins, metal binding proteins, redox active cysteines, and glutathionylation sites in proteins. Finally, we have a page devoted to advances in redox medicine with a primary focus on cancer, ...
We developed camptothecin (CPT)-conjugated, core-cross-linked (CCL) micelles that are subject to redox-responsive cleavage of the built-in disulfide bonds, resulting in disruption of the micellar structure and rapid release of CPT. CCL micelles were prepared via coprecipitation of disulfide-containing CPT-poly(tyrosine(alkynyl)-OCA) conjugate and monomethoxy poly(ethylene glycol)-b-poly(tyrosine(alkynyl)-OCA), followed by cross-linking of the micellar core via azide-alkyne click chemistry. CCL micelles exhibited excellent stability under physiological conditions, while they underwent rapid dissociation in reduction circumstance, resulting in burst release of CPT. These redox-responsive CCL micelles showed enhanced cytotoxicity against human breast cancer cells in vitro. Wang, Hua; Tang, Li; Tu, Chunlai; Song, Ziyuan; Yin, Qian; Yin, Lichen; Zhang, Zhonghai; Cheng, Jianjun
Chapter 4: Oxidation - Reduction Reactions. Oxidation - Reduction Reactions involve the gain and loss of electrons. The species involved in these reactions may be atoms, molecules,or ions. Cation : a positively charged ion. (More protons than electrons.) Slideshow 807033 by valterra
The heart relies predominantly on a balance between fatty acids and glucose to generate its energy supply. There is an important interaction between the metabolic pathways of these two substrates in the heart. When circulating levels of fatty acids are high, fatty acid oxidation can dominate over glucose oxidation as a source of energy through feedback inhibition of the glucose oxidation pathway. Following an ischaemic episode, fatty acid oxidation rates increase further, resulting in an uncoupling between glycolysis and glucose oxidation. This uncoupling results in an increased proton production, which worsens ischaemic damage. Since high rates of fatty acid oxidation can contribute to ischaemic damage by inhibiting glucose oxidation, it is important to maintain proper control of fatty acid oxidation both during and following ischaemia. An important molecule that controls myocardial fatty acid oxidation is malonyl-CoA, which inhibits uptake of fatty acids into the mitochondria. The levels of ...
Oxidation & reduction MCQ quiz, oxidation & reduction multiple choice questions answers, online chemistry quiz MCQs old paintings can be restored through oxidizing agent with answers.
Surfactant Enhanced In-situ Chemical Oxidation by VeruTEK Technologies, Inc.. VeruTEK’s patented S-ISCO (Surfactant Enhanced In-situ Chemical Oxidation) process incorporates VeruSOL, a biodegradable, plant-based surfactant/co-solvent mixture th...
Conventional and nanostructured YSZ coatings were deposited on the IN-738 Ni super alloy by the atmospheric plasma spray technique. The oxidation was measured at 1100°C in an atmospheric electrical furnace. According to the experimental results the nanostructured coatings showed a better oxidation resistance than the conventional ones. The improved oxidation resistance of the nanocoating could be explained by the change in structure to a dense and more packed structure in this coating. The mechanical properties of the coatings were tested using the thermal cyclic, nanoindentation and bond strength tests, during which the nanostructured YSZ coating showed a better performance by structural stability.
The importance of oxidation-reduction reactions was recognized from the beginning of chemistry. In oxidation-reduction, some entity is given or taken between two reacting chemicals. The situation is similar to that in acid-base reactions. In brief, oxidation-reduction and acid-base reactions form a pair of systems in chemistry. Oxidation-reduction and acid-base reactions share a common feature in that both had been put into practice before the nature of the reactions was clarified. Important concepts have gradually been developed: for example, the oxidation number, an oxidant (an oxidizing agent), a reductant (a reducing agent), electromotive force, Nernsts equation, Faradays law of electromagnetic induction, and electrolysis. The development of electric cells was significant. Assembling the components of an oxidation-reduction reaction is good practice and a satisfying intellectual challenge. Cells and electrolysis are two particularly important examples because both are strongly related to everyday
Chapter 5 Oxidation Reduction Reactions Chemistry: The Molecular Nature of Matter, 7E Jespersen/Hyslop Chapter in Context Define oxidation, reduction, oxidizing agents, reducing agents, and oxidation numbers
Volume 33: Future Vision of Advanced Oxidation Process and its Immediate Efficacy - A Deep, Insightful Comprehension and a Far-Reaching Review
Patchy occurrences of elevated As are often encountered in groundwater from the shallow aquifers (,50 m) of the Bengal Delta Plain (BDP). A clear understanding of various biogeochemical processes, responsible for As mobilization, is very important to explain this patchy occurrence and thus to mitigate the problem. The present study deals with the periodical monitoring of groundwater quality of five nested piezometeric wells between December 2008 and July 2009 to investigate the temporal changes in groundwater chemistry vis-a-vis the prevalent redox processes in the aquifer. Geochemical modeling has been carried out to identify key phases present in groundwater. A correlation study among different aqueous redox parameters has also been performed to evaluate prevailing redox processes in the aquifer. The long term monitoring of hydrochemical parameters in the multilevel wells together with hydrogeochemical equilibrium modeling has shown more subtle differences in the geochemical environment of the ...
ATP-hydrolysis and proton pumping by the V-ATPase (vacuolar proton-translocating ATPase) are subject to redox regulation in mammals, yeast and plants. Oxidative inhibition of the V-ATPase is ascribed to disulfide-bond formation between conserved cysteine residues at the catalytic site of subunit A. Subunits containing amino acid substitutions of one of three conserved cysteine residues of VHA-A were expressed in a vha-A null mutant background in Arabidopsis. In vitro activity measurements revealed a complete absence of oxidative inhibition in the transgenic line expressing VHA-A C256S, confirming that Cys256 is necessary for redox regulation. In contrast, oxidative inhibition was unaffected in plants expressing VHA-A C279S and VHA-A C535S, indicating that disulfide bridges involving these cysteine residues are not essential for oxidative inhibition. In vivo data suggest that oxidative inhibition might not represent a general regulatory mechanism in plants. ...
Locate Oxidation Reduction Potential (ORP) Electrodes suppliers, manufacturers & distributors in District of Columbia. Interactive map of District of Columbia provided.
Locate Oxidation Reduction Potential (ORP) Instruments suppliers, manufacturers & distributors in California. Interactive map of California provided.
2 Sheets-Sheet 1 w. L. HENDERSON I CATALYTIC OXIDATION UNIT FOR DOMESTIC OVEN EXHAUST Oct. 27,1970 Filed Feb WAYNE L. HENDERSON ms ATTORNEY Oct. 27 41970 w, HENDERSON 3,536,?!- CATALYTIC OXIDATION UNIT FOR DOMESTIC-OVENBXIIAUST Filed Feb. 21, 1968 2 shms snm a was I FIG.4 . l I I l I I I I I I I I I o "5 l 3o 4o so 6o INVENTOIL WAYNE L. neuoaasou HIS ATTORNEY United States Patent US. Cl. 23-288 2 Claims ABSTRACT OF THE DISCLOSURE A catalytic oxidation unit useful in eliminating smoke and odors issuing from the exhaust vent of a domestic cooking oven, particularly a high temperature, selfcleaning oven using a pyrolytic process for degrading food soils. The oxidation unit comprises a hollow housing supporting a plurality of catalyst coated gas burners of cellular ceramic construction and having a high surface-tovolume ratio. The housing has an intake port and an exhaust port and includes a partition which separates the housing into intake and afterburner compartments; with the gas flow being ...
TY - JOUR. T1 - Enhanced tissue production through redox control in stem cell-laden hydrogels. AU - Reid, Branden. AU - Afzal, Junaid M.. AU - Mccartney, Annemarie M.. AU - Abraham, M. Roselle. AU - ORourke, Brian. AU - Elisseeff, Jennifer Hartt. PY - 2013/9/1. Y1 - 2013/9/1. N2 - Cellular bioenergetics and redox (reduction-oxidation) play an important role in cell proliferation and differentiation, key aspects of building new tissues. In the present study, we examined the metabolic characteristics of human adipose-derived stem cells (hASCs) during proliferation and differentiation in both monolayer and three-dimensional biomaterial scaffolds. In monolayer, hASCs exhibited higher glycolysis and lower ox-phos as compared to both adipogenic and osteogenic differentiated cells, and hASCs demonstrated the Warburg effect (aerobic glycolysis). However, reactive oxygen species (ROS) levels increased during adipogenic differentiation, but decreased during osteogenic differentiation. Similarly, a ...
It is crucial to develop a catalyst made of earth-abundant elements highly active for a complete oxidation of methane at a relatively low temperature. NiCo2O4 consisting of earth-abundant elements which can completely oxidize methane in the temperature range of 350-550 °C. Being a cost-effective catalyst, NiCo2O4 exhibits activity higher than precious-metal-based catalysts. Here we report that the higher catalytic activity at the relatively low temperature results from the integration of nickel cations, cobalt cations and surface lattice oxygen atoms/oxygen vacancies at the atomic scale. In situ studies of complete oxidation of methane on NiCo2O4 and theoretical simulations show that methane dissociates to methyl on nickel cations and then couple with surface lattice oxygen atoms to form -CH3O with a following dehydrogenation to −CH2O; a following oxidative dehydrogenation forms CHO; CHO is transformed to product molecules through two different sub-pathways including dehydrogenation of OCHO ...
Free Online Library: Prepartum body condition score affects milk yield, lipid metabolism, and oxidation status of Holstein cows. by Asian - Australasian Journal of Animal Sciences; Agricultural industry Biological sciences College football Analysis Physiological aspects Dairy industry Dairy products industry Enzyme-linked immunosorbent assay Enzymes Fatty acids Football (College) Superoxide Superoxides Vitamin A
Article In Situ Chemical Oxidation Remediation Pilot Study Of A Karst Bedrock Aquifer Contaminated With Chlorinated Solvents. ABSTRACT A pilot study to evaluate an innovative in situ treatment technology was implemented at Letterkenny Army Depot, ...
Thermal treatments prior or during chemical oxidation of aged polycyclic aromatic hydrocarbon (PAH)-contaminated soils have already shown their ability to
Free practice questions for High School Chemistry - Balancing Oxidation-Reduction Reactions. Includes full solutions and score reporting.
The thermodynamics for the first electron transfer step for sulfide and oxygen indicates that the reaction is unfavorable as unstable superoxide and bisulfide radical ions would need to be produced. However, a two electron transfer is favorable as stable S(0) and peroxide would be formed, but the partially filled orbitals in oxygen that accept electrons prevent rapid kinetics. Abiotic sulfide oxidation kinetics improve when reduced iron and/or manganese are oxidized by oxygen to form oxidized metals which in turn oxidize sulfide. Biological sulfur oxidation relies on enzymes that have evolved to overcome these kinetic constraints to affect rapid sulfide oxidation. Here we review the available thermodynamic and kinetic data for H2S and HS• as well as O2, reactive oxygen species, nitrate, nitrite and NOx species. We also present new kinetic data for abiotic sulfide oxidation with oxygen in trace metal clean solutions that constrain abiotic rates of sulfide oxidation in metal free solution and agree with
MCOs catalyze one-electron oxidation processes, and four molecules of substrate are oxidised in order to reduce a dioxygen molecule to two waters molecules. Substrate oxidation occurs at the mononuclear T1 centre and then the electrons are shuttled, along a T1 coordinating cisteine, to the two histidines that are coordinating the T3 coppers of the trinuclear centre (Figure 1b), where reduction of dioxygen occurs [2, 4, 11]. This constitutes a HCH conserved motif characteristically found in MCOs. Four electrons, as well as four protons, are used to reduce a molecule of dioxygen with the concomitant formation of two water molecules [1, 2, 12]. Electrons needed for this process are obtained through the oxidation of a variety of substrates, but not much is known about the mechanism of proton transfer during this process. Recently, site directed mutagenesis studies suggest that Asp112 of CueO (Asp 116 in CotA; Figure 1c) [13, 14], a conserved residue that is located in the exit channel in close ...
Recall that chemical reactions are all about electrons. In redox (an often used shorthand term for oxidation-reduction) reactions, one is concerned with how electrons are transferred from one species (element, ion, compound) to another. The law of conservation of charge stipulates that if one species loses electrons, there must be another species that gains the electrons. The term oxidation refers to any process that loses electrons. This is a tricky word for some because oxidation sounds like it might only involve oxygen. In truth, oxygen is an important element in redox reactions, and because of its large electronegativity, causes many other elements to give it electrons. Since oxygen often "forces" other elements to lose electrons, the process of losing electrons became known as oxidation. Reduction is a similarly troubling word, since it refers to a process that gains electrons. In this case, the word "reduce" has nothing to do with the quantity of electrons, but rather the change in charge. ...