A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
Influence of a new antiulcer agent, ammonium 7-oxobicyclo (2, 2, 1) hept-5-ene-3-carbamoyl-2-carboxylate (KF-392) on gastric lesions and gastric mucosal barrier in rats. (1/661)Antiulcer effects of KF-392 were studied in several experimental gastric ulcer models in rats. It was found that KF-392 given orally at 1.0 to 5.0 mg/kg had a marked suppression on the developments of Shay ulcer as well as the aspirin-, stress-, and reserpine-induced gastric lesions. The influence of KF-392 on gastric mucosal barrier was also studied. A back diffusion of H+ into the gastric mucosa and a fall of transmucosal potential difference were induced with KF-392 given orally at the above mentioned doses. KF-392 given s.c. at 5.0 mg/kg showed no inhibition of Shay ulcer and no induction of back diffusion of H+ into the gastric mucosa. (+info)
Potential difference across the normal and the abnormal gastric mucosa in man. (2/661)The mucosal potential difference in the body of the stomach was measured in 18 patients with gastric ulcers, five with gastritis, and three with pernicious anaemia. The results were compared with those of 12 normal volunteers. Significantly lower than normal levels were found in the groups of patients with gastric ulcers and gastritis. The patients with pernicious anaemia had even lower potential differences. In an additional 25 subjects, measurements were made in the duodenal bulb and at five sites in the stomach under direct vision at endoscopy. Biopsies were taken from each site for histology. Subjects with gastritis at the high lesser curve had a significantly lower potential difference at that site than those without gastritis. In the latter group, the potential difference at the high lesser curve was as low as in the antrum, and invariably lower than at the high greater curve. (+info)
Characterization of DorC from Rhodobacter capsulatus, a c-type cytochrome involved in electron transfer to dimethyl sulfoxide reductase. (3/661)The dorC gene of the dimethyl sulfoxide respiratory (dor) operon of Rhodobacter capsulatus encodes a pentaheme c-type cytochrome that is involved in electron transfer from ubiquinol to periplasmic dimethyl sulfoxide reductase. DorC was expressed as a C-terminal fusion to an 8-amino acid FLAG epitope and was purified from detergent-solubilized membranes by ion exchange chromatography and immunoaffinity chromatography. The DorC protein had a subunit Mr = 46,000, and pyridine hemochrome analysis indicated that it contained 5 mol heme c/mol DorC polypeptide, as predicted from the derived amino acid sequence of the dorC gene. The reduced form of DorC exhibited visible absorption maxima at 551.5 nm (alpha-band), 522 nm (beta-band), and 419 nm (Soret band). Redox potentiometry of the heme centers of DorC identified five components (n = 1) with midpoint potentials of -34, -128, -184, -185, and -276 mV. Despite the low redox potentials of the heme centers, DorC was reduced by duroquinol and was oxidized by dimethyl sulfoxide reductase. (+info)
Redox components of cytochrome bc-type enzymes in acidophilic prokaryotes. I. Characterization of the cytochrome bc1-type complex of the acidophilic ferrous ion-oxidizing bacterium Thiobacillus ferrooxidans. (4/661)The redox components of the cytochrome bc1 complex from the acidophilic chemolithotrophic organism Thiobacillus ferrooxidans were investigated by potentiometric and spectroscopic techniques. Optical redox titrations demonstrated the presence of two b-type hemes with differing redox midpoint potentials at pH 7.4 (-169 and + 20 mV for bL and bH, respectively). At pH 3.5, by contrast, both hemes appeared to titrate at about +20 mV. Antimycin A, 2-heptyl-4-hydroxyquinoline N-oxide, and stigmatellin induced distinguishable shifts of the b hemes' alpha-bands, providing evidence for the binding of antimycin A and 2-heptyl-4-hydroxyquinoline N-oxide near heme bH (located on the cytosolic side of the membrane) and of stigmatellin near heme bL (located on the periplasmic side of the membrane). The inhibitors stigmatellin, 5-(n-undecyl)-6-hydroxy-4,7-dioxobenzothiazole, and 2, 5-dibromo-3-methyl-6-isopropyl-p-benzoquinone affected the EPR spectrum of the Rieske iron-sulfur center in a way that differs from what has been observed for cytochrome bc1 or b6f complexes. The results obtained demonstrate that the T. ferrooxidans complex, although showing most of the features characteristic for bc1 complexes, contains unique properties that are most probably related to the chemolithotrophicity and/or acidophilicity of its parent organism. A speculative model for reverse electron transfer through the T. ferrooxidans complex is proposed. (+info)
Redox components of cytochrome bc-type enzymes in acidophilic prokaryotes. II. The Rieske protein of phylogenetically distant acidophilic organisms. (5/661)The Rieske proteins of two phylogenetically distant acidophilic organisms, i.e. the proteobacterium Thiobacillus ferrooxidans and the crenarchaeon Sulfolobus acidocaldarius, were studied by EPR. Redox titrations at a range of pH values showed that the Rieske centers of both organisms are characterized by redox midpoint potential-versus-pH curves featuring a common pK value of 6.2. This pK value is significantly more acidic (by almost 2 pH units) than that of Rieske proteins in neutrophilic species. The orientations of the Rieske center's g tensors with respect to the plane of the membrane were studied between pH 4 and 8 using partially ordered samples. At pH 4, the Sulfolobus Rieske cluster was found in the "typical" orientation of chemically reduced Rieske centers, whereas this orientation changed significantly on going toward high pH values. The Thiobacillus protein, by contrast, appeared to be in the "standard" orientation at both low and high pH values. The results are discussed with respect to the molecular parameters conveying acid resistance and in light of the recently demonstrated long-range conformational movement of the Rieske protein during enzyme turnover in cytochrome bc1 complexes. (+info)
Extinction coefficients and midpoint potentials of cytochrome c(6) from the cyanobacteria Arthrospira maxima, Microcystis aeruginosa, and Synechocystis 6803. (6/661)Cytochrome c(6) is a soluble heme protein that serves as a photosynthetic electron transport component in cyanobacteria and algae, carrying electrons from the cytochrome bf complex to photosystem I. The rapid accumulation of cytochrome c(6) sequence data from a wide range of species, combined with significant advances in determining high resolution three-dimensional structures, provides a powerful database for investigating the relationship between structure and function. The fact that the gene encoding cytochrome c(6) can be readily modified in a number of species adds to the usefulness of cytochrome c(6) as a tool for comparative analysis. Efforts to relate cytochrome c(6) sequence information to structure, and structural information to function depend on knowledge of the physical and thermodynamic properties of the cytochrome from different species. To this end we have determined the optical extinction coefficient, the oxidation/reduction midpoint potential, and the pH dependence of the midpoint potential of cytochrome c(6) isolated from three cyanobacteria, Arthrospira maxima, Microcystis aeruginosa, and Synechocystis 6803. (+info)
Donnan potential of rabbit skeletal muscle myofibrils I: electrofluorochromometric detection of potential. (7/661)The fluorescence of the dye CC-6 [(3-hexyl-2-(3-hexyl-2-benzoxazolinylidene)-1-propenyl)-benzoxazolium iodide] has been shown to indicate Donnan potentials in rabbit skeletal muscle myofibrils. These results are in agreement with previously published work in which the potentials were measured with microelectrodes on glycerol-extraced muscle fibers. The magnitude of the Donnan potential of the myofibrils has been shown to be dependent on the state (rigor or relaxed) of the system. (+info)
A group of thermodynamic potentials applicable to ligand binding by a polyfunctional macromolecule. (8/661)The binding of ligands by a macromolecule can be well described by a group of potentials derivable from the energy and of which the original binding potential is one. The group is Abelian and is isomorphic with a group of symmetries. Each member corresponds to a particular set of experimental conditions--system open to some, closed to others, of the ligand-and the group as a whole is an immediate source of all possible linkage relations applicable to the macromolecule. Seen in terms of information theory it can be interpreted as a program for the response of the macromolecule to its ligands according to the conditions with which it is faced. The group provides a ready formulation of the effect of a ligand on the equilibrium constant for a reaction involving a set of macromolecules, and it leads to a clear-cut distinction between true and pseudolinkage. (+info)
She has published several science books, including: 1969 - Chemical Applications of Potentiometry 1970 - H2O 1971 - Metals 1975 ... Rossotti, Hazel (1969). Chemical applications of potentiometry. London: Van Nostrand. ISBN 978-0442070489. OCLC 36088. Rossotti ...
A variant of potentiometry is chronopotentiometry which consists in using a constant current and measurement of potential as a ... Potentiometry usually uses indicator electrodes made selectively sensitive to the ion of interest, such as fluoride in fluoride ... doi:10.1016/0045-6535(94)90303-4. Noyhouzer, T.; Valdinger, I.; Mandler, D. (2013-09-03). "Enhanced Potentiometry by Metallic ... The three main categories are potentiometry (the difference in electrode potentials is measured), amperometry (electric current ...
Scanning probe microscopy
... scanning tunneling potentiometry SXSTM, synchrotron x-ray scanning tunneling microscopy SPE, Scanning Probe Electrochemistry ... "High resolution atomic force microscopy potentiometry". Journal of Vacuum Science and Technology B. 9 (3): 1559-1561. Bibcode: ...
Bürgi, L.; Sirringhaus, H.; Friend, R. H. (2002). "Noncontact potentiometry of polymer field-effect transistors". Applied ...
LCCN 20-20413 Hazel Rossotti, "Chemical applications of potentiometry". London, Princeton, N.J., Van Nostrand, 1969. ISBN 0-442 ...
Bishop (1965-07-01). "Concentration Overpotentials on Antimony Electrodes in Differential Electrolytic Potentiometry". ...
Multi-tip scanning tunneling microscopy
Potentiometry maps give insight into fundamental transport properties, such as the influence of defects on the local electric ... Lüpke, F; Korte, S; Cherepanov, V & Voigtländer, B (2015). "Scanning tunneling potentiometry implemented into a multi-tip setup ... A method giving valuable insight into the charge transport properties of nanostructures is the scanning tunneling potentiometry ...
Scanning tunneling microscope
... scanning tunneling potentiometry (STP), which measures electric potential across a surface; spin polarized scanning tunneling ...
Determination of equilibrium constants
Neither potentiometry nor ultraviolet-visible spectroscopy could be used for this determination. Limited precision of chemical ...
Amperostat Coulometry Electroanalytical method Galvanostat Operational amplifier Polarography Potentiometry Voltammetry Bard, A ...
Carbon paste electrode
... both amperometry and potentiometry). In general, CPEs are popular because carbon pastes are easily obtainable at minimal costs ...
The three main sections of this type of analysis are potentiometry, coulometry and voltammetry. Potentiometry measures the ...
... content of samples is determined by atomic absorption spectrophotometry or by potentiometry using ion-selective ...
Sodium content of samples is determined by atomic absorption spectrophotometry or by potentiometry using ion-selective ...
Potentiometry Ion-selective electrodes ISFET pH electrode Chalcogenide glass Quinhydrone electrode Solid State Electrode Bates ...
Malmstadt's major areas of research were in precision null-point potentiometry, emission and absorption spectrochemical methods ...
Low-energy electron microscopy
Other advanced techniques include: Low-Energy Electron Potentiometry: Determining the shift of LEEM spectra allows the ...
Electrochemical stripping analysis
... is a set of analytical chemistry methods based on voltammetry or potentiometry that are used ...
Antimony electrode Ion-selective electrodes ISFET pH electrode Potentiometry Quinhydrone electrode Saturated calomel electrode ...
... redox potentiometry, and steady-state enzyme kinetics. Following is a table of selected substrates, inducers and inhibitors of ...
Electrolyte exclusion effect
... an error affecting measurements made by either flame photometry or indirect potentiometry but not by direct potentiometry. The ...
Karl Fischer titration
... which can be detected by potentiometry. The reaction is run in an alcohol solution containing a base, which consumes the sulfur ...
They included acid-base titrimetry, electrometric analysis and conductometry, potentiometry, electron transfer, gravimetric ...
Total base number
"Basics of potentiometry". Metrohm.com. ASTM D4739-11, Standard Test Method for Base Number Determination by Potentiometric ...
... potentiometry, or acidic potassium permanganate chemiluminescence. There are quantitative differences between the two species ...
... an English pioneer of vacuum-tube potentiometry with George Zaidan. "Local Roseworthy Successes". The Mount Barker Courier And ...
List of MeSH codes (H01)
... potentiometry MeSH H01.181.529.328 - energy transfer MeSH H01.181.529.328.400 - linear energy transfer MeSH H01.181.529.365 - ...
List of MeSH codes (E05)
... potentiometry MeSH E05.196.922.875 - skin test end-point titration MeSH E05.196.941.336 - centrifugation, density gradient MeSH ...
The four main categories are potentiometry (the difference in electrode potentials is measured), coulometry (the transferred ...
... metal-oxide-semiconductor field-effect transistor pH pH meter Potentiometry Quinhydrone electrode Saturated calomel electrode ...
Ammonia electrode membrane caps - HORIBA
Automatic Titrator with IDS Technology for Exchangeable Heads for Potentiometry and KF - ScienceGates Sdn Bhd
Home / Potentiometric Titrators / Automatic Titrator with IDS Technology for Exchangeable Heads for Potentiometry and KF. ... Automatic Titrator with IDS Technology for Exchangeable Heads for Potentiometry and KF. Price On Request ... Automatic Titrator with IDS Technology for Exchangeable Heads for Potentiometry and KF quantity. ...
Course Outlines - Simon Fraser University
France - APTYS | WHO - Prequalification of Medical Products (IVDs, Medicines, Vaccines and Immunization Devices, Vector Control)
The EPA National Library Catalog | EPA National Library Network | US EPA
Environments | Free Full-Text | Copper Complexation by Dissolved Organic Matter in arid Soils: A Voltametric Study
Biphasic composite of calcium phosphate-based mesoporous silica as a novel bone drug delivery system | SpringerLink
Chemistry | Undergraduate Catalog - University of St. Thomas - Minnesota
Chemistry Minor | Aquinas College
Lab 7: Absorption Spectra of Conjugated Dyes - Chemistry LibreTexts
Epigraphene | Publications
Pharmaceutical Analysis-I (RNPD B. Pharm. Series) | B. Pharm Books & Study Material- RNPD
Potenciometrijsko određivanje aktivnih spojeva e elektrodama na bazi ugljikove paste - pregledni rad | Repozitorij Kemijsko...
مجتمع ها | دانلود مقالات ISI مجتمع ها | 776 مقاله انگلیسی + ترجمه فارسی
GPAT Syllabus 2023 - Check Subject-Wise Topics Included, Exam Preparation Tips!
Child's consumption of drinks milk: total soluble solids (Brix) and pH
Lazouskaya, M., Scheler, O., Uppuluri, K., Zaraska, K., Tamm, M. - TalTech teadusportaal
Monitoring anionskih tenzida u otpadnim vodama industrije detergenata za veljaču 2014. | Repozitorij Odjela za kemiju, Osijek
Pesquisa | Biblioteca Virtual em Saúde - BRASIL
In this study, a fluorescent coumarin derivative of DFO (DFOC) has been prepared and characterized (potentiometry, UV-Vis ... First, solution equilibria involving ligands and complexes were analyzed (potentiometry, NMR, UV-vis, ITC). Then, the ... have been studied by potentiometry, NMR, UV-Vis and fluorescence spectroscopy and isothermal titration calorimetry (ITC). The ...
Gabriel Martínez: Web Developer Portfolio
ИСО - 39.060
Classes - Koley Lab
CHEM 4622 - Analytical Chemistry II 4 s.h. - Acalog ACMS™
Chemistry (CHEM) | University of New Hampshire
Advantages of volumetric analysis. A Brief Analysis Of Volumetric Analysis Titration. 2022-10-21
CICECO Publication » Selective recognition of tetrahedral dianions by a hexaaza cryptand receptor
- In practice, it is used in coulometry, voltmetry, amperometry and potentiometry in pharmaceutical tests, measuring harmful metals in water samples, as a glucose biosensor, for measuring tumor markers and cholesterol in the blood, detection of microorganisms. (ktf-split.hr)
- Some of the topics covered in this course are as follows: Potentiometry, Amperometry, SECM, Electrochemical Biosensors, photoelectrochemistry etc. (koleylab.com)
- Laboratory experiences include absorbance and fluorescence spectrophotometry, atomic spectroscopy, potentiometry, voltammetry, liquid and gas chromatography and mass spectrometry. (oneonta.edu)
- I performed the analyzes by potentiometry, titrimetry, and high-efficiency liquid chromatography. (gabrielmr.com)
- Titrimetric (e.g. acid-base, EDTA) and electroanalytical techniques (e.g. potentiometry and voltammetry) for solution species are performed. (sfu.ca)
- Michaelis, Kolthoff Clarke, Muller, Furman, and Jorgensen performed work on the determination of pH using potentiometry and reported their work in the first half of the 20th century. (columbia.edu)
- The synthesis, acid-base behaviour and anion recognition of neurotransmitters (dopamine, tyramine and serotonin) in aqueous solution of different aza-scorpiand ligands functionalized with hydroxyphenyl and phenyl moieties (L1-L3 and L4, respectively) have been studied by potentiometry, NMR, UV-Vis and fluorescence spectroscopy and isothermal titration calorimetry (ITC). (bvsalud.org)
- Potentiometry with CPE has proven to be just as good or better than conventional measurement methods - it is cheaper, simpler, faster and has a lower detection threshold. (ktf-split.hr)
- This phenomenon, known as pseudohyponatremia, occurs when flame emission spectrophotometry or indirect potentiometry is used to assay serum sodium levels rather than direct potentiometry techniques. (medscape.com)