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Oxidase Negative
The oxidase test is used to determine whether an organism possesses the cytochrome c oxidase enzyme. The test is used as an aid for the differentiation of ''Neisseria'', ''Moraxella'', ''Campylobacter'' and ''Pasteurella'' species (oxidase positive). It is also used to differentiate pseudomonads from related species.MacFaddin JF, editor. Biochemical Tests for Identification of Medical Bacteria. 3rd ed. Philadelphia:Lippincott Williams and Wilkins; 2000. p. 363-7 Classification Strains may be either oxidase-positive (OX+) or oxidase-negative (OX-). OX+ OX+ normally means the bacterium contains cytochrome c oxidase (also known as Complex IV) and can therefore use oxygen for energy production by converting O2 to H2O2 or H2O with an electron transfer chain. The Pseudomonadaceae are typically OX+. The Gram-negative diplococci Neisseria and Moraxella are oxidase-positive. Many Gram-negative, spiral curved rods are also oxidase-positive, which includes ''Helicobacter pylori'', ''Vibrio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytochrome C Oxidase
The enzyme cytochrome c oxidase or Complex IV (was , now reclassified as a translocasEC 7.1.1.9 is a large transmembrane protein complex found in bacteria, archaea, and the mitochondria of eukaryotes. It is the last enzyme in the Cellular respiration, respiratory electron transport chain of cell (biology), cells located in the membrane. It receives an electron from each of four cytochrome c molecules and transfers them to one oxygen molecule and four protons, producing two molecules of water. In addition to binding the four protons from the inner aqueous phase, it transports another four protons across the membrane, increasing the transmembrane difference of proton electrochemical potential, which the ATP synthase then uses to synthesize Adenosine triphosphate, ATP. Structure The complex The complex is a large integral membrane protein composed of several Cofactor (biochemistry)#Metal ions, metal prosthetic sites and 13 protein subunits in mammals. In mammals, ten subunits a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sterile Technique
Asepsis is the state of being free from disease-causing micro-organisms (such as pathogenic bacteria, viruses, pathogenic fungi, and parasites). There are two categories of asepsis: medical and surgical. The modern day notion of asepsis is derived from the older antiseptic techniques, a shift initiated by different individuals in the 19th century who introduced practices such as the sterilizing of surgical tools and the wearing of surgical gloves during operations. The goal of asepsis is to eliminate infection, not to achieve sterility. Ideally, an operating field is sterile, meaning it is free of all biological contaminants (e.g. fungi, bacteria, viruses), not just those that can cause disease, putrefaction, or fermentation. Even in an aseptic state, a condition of sterile inflammation may develop. The term often refers to those practices used to promote or induce asepsis in an operative field of surgery or medicine to prevent infection. History The modern concept of asepsis e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trypticase Soy Agar
Trypticase soy agar or Tryptic soy agar (TSA) is a growth medium, growth media for the microbiological culture, culturing of moderately to non fastidious organism , fastidious bacteria. It is a general-purpose, non-selective media providing enough nutrients to allow for a wide variety of microorganisms to grow. It is used for a wide range of applications, including culture storage, enumeration of cells (counting), isolation of pure cultures, or simply general culture. TSA contains enzymatic digests of casein and soybean meal, which provide amino acids and other nitrogenous substances, making it a nutritious medium for a variety of organisms. Sodium chloride maintains the osmotic equilibrium, while dipotassium phosphate acts as buffering agent, buffer to maintain pH. Agar extracted from any number of organisms is used as a gelling agent. One liter of the agar contains: * 15 g tryptone, pancreatic digest of casein * 5 g soytone, peptic digest of soybean * 5 g sodium chloride * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalase Test
Catalase is a common enzyme found in nearly all living organisms exposed to oxygen (such as bacteria, plants, and animals) which catalyzes the decomposition of hydrogen peroxide to water and oxygen. It is a very important enzyme in protecting the cell from oxidative damage by reactive oxygen species (ROS). Catalase has one of the highest turnover numbers of all enzymes; one catalase molecule can convert millions of hydrogen peroxide molecules to water and oxygen each second. Catalase is a tetramer of four polypeptide chains, each over 500 amino acids long. It contains four iron-containing heme groups that allow the enzyme to react with hydrogen peroxide. The optimum pH for human catalase is approximately 7, and has a fairly broad maximum: the rate of reaction does not change appreciably between pH 6.8 and 7.5. The pH optimum for other catalases varies between 4 and 11 depending on the species. The optimum temperature also varies by species. Structure Human catalase forms a t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indophenol Blue
Indophenol is an organic compound with the formula OC6H4NC6H4OH. It is deep blue dye that is the product of the Berthelot's reaction, a common test for ammonia. The indophenol group, with various substituents in place of O''H'' and various ring substitutions, is found in many dyes used in hair coloring and textiles. Indophenol is used in hair dyes, lubricants, redox materials, liquid crystal displays, fuel cells and chemical-mechanical polishing. It is an environmental pollutant and is toxic to fish. Berthelot test In the Berthelot test (1859), a sample suspected of containing ammonia is treated with sodium hypochlorite and phenol. The formation of indophenol is used to determine ammonia and paracetamol by spectrophotometry. Other phenols can be used. Dichlorophenol-indophenol (DCPIP), a form of indophenol, is often used to determine the presence of vitamin C (ascorbic acid). Related compounds Indophenol blue is a different compound with systematic name A systematic name i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NADH
Nicotinamide adenine dinucleotide (NAD) is a coenzyme central to metabolism. Found in all living cells, NAD is called a dinucleotide because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an adenine nucleobase and the other, nicotinamide. NAD exists in two forms: an oxidized and reduced form, abbreviated as NAD and NADH (H for hydrogen), respectively. In cellular metabolism, NAD is involved in redox reactions, carrying electrons from one reaction to another, so it is found in two forms: NAD is an oxidizing agent, accepting electrons from other molecules and becoming reduced; with H+, this reaction forms NADH, which can be used as a reducing agent to donate electrons. These electron transfer reactions are the main function of NAD. It is also used in other cellular processes, most notably as a substrate of enzymes in adding or removing chemical groups to or from proteins, in posttranslational modifications. Because of the import ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indophenol Oxidase
Indophenol is an organic compound with the formula OC6H4NC6H4OH. It is deep blue dye that is the product of the Berthelot's reaction, a common test for ammonia. The indophenol group, with various substituents in place of O''H'' and various ring substitutions, is found in many dyes used in hair coloring and textiles. Indophenol is used in hair dyes, lubricants, redox materials, liquid crystal displays, fuel cells and chemical-mechanical polishing. It is an environmental pollutant and is toxic to fish. Berthelot test In the Berthelot test (1859), a sample suspected of containing ammonia is treated with sodium hypochlorite and phenol. The formation of indophenol is used to determine ammonia and paracetamol by spectrophotometry. Other phenols can be used. Dichlorophenol-indophenol (DCPIP), a form of indophenol, is often used to determine the presence of vitamin C (ascorbic acid). Related compounds Indophenol blue is a different compound with systematic name A systematic name i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maroon (color)
Maroon ( , ) is a brownish crimson color that takes its name from the French word , meaning chestnut. ''Marron'' is also one of the French translations for "brown". Terms describing interchangeable shades, with overlapping RGB ranges, include burgundy, claret, mulberry, and crimson. Different dictionaries define maroon differently. The ''Cambridge English Dictionary'' defines maroon as a dark reddish-purple color while its "American Dictionary" section defines maroon as dark brown-red. Lexico online dictionary defines maroon as a brownish-red. Similarly, Dictionary.com defines maroon as a dark brownish-red. The '' Shorter Oxford English Dictionary'' describes maroon as "a brownish- crimson or claret colour," while the Merriam-Webster online dictionary simply defines it as a dark red. In the sRGB color model for additive color representation, the web color called maroon is created by turning down the brightness of pure red to about one half. It is also noted that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redox
Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. The oxidation and reduction processes occur simultaneously in the chemical reaction. There are two classes of redox reactions: * Electron transfer, Electron-transfer – Only one (usually) electron flows from the atom, ion, or molecule being oxidized to the atom, ion, or molecule that is reduced. This type of redox reaction is often discussed in terms of redox couples and electrode potentials. * Atom transfer – An atom transfers from one Substrate (chemistry), substrate to another. For example, in the rusting of iron, the oxidation state of iron atoms increases as the iron converts to an oxide, and simultaneously, the oxidation state of oxygen decreases as it accepts electrons r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DMPD
''N'',''N''-Dimethylphenylenediamine is an organic compound with the formula . It is one of the phenylenediamines, a class of compounds that have long attracted attention for their redox properties. This diamine is, for example, easily oxidized to a deep red radical cation, which is called Wurster's Red. The related Wurster's Blue cation has four N-methyl groups Synthesis Dimethyl-4-phenylenediamine is prepared by the nitration of dimethylaniline followed by reduction of the resulting 4-nitrodimethylaniline. A variety of methods have been examined. Applications Dimethyl-4-phenylenediamine can be converted to methylene blue by reaction with dimethylaniline and sodium thiosulfate in several steps: : It reacts with carbon disulfide Carbon disulfide (also spelled as carbon disulphide) is an inorganic compound with the chemical formula and structure . It is also considered as the anhydride of thiocarbonic acid. It is a colorless, flammable, neurotoxic liquid that is used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wurster's Blue
Tetramethylphenylenediamine (TMPD) is an organic compound with the formula . It is most studied of three isomers of this formula. It is a colorless solid. With two dimethylamino substituents, the ring is particularly electron rich. Redox behavior One-electron oxidation of TMPD gives the deep blue radical cation called Wurster's blue, . It was one of the first radical cations to be reported. Many properties have been described including its rapid rate of Outer sphere electron transfer, self-exchange: : X-ray crystallography of the TMPD and its iodide salt reveals that oxidation most strongly contracts the C-N(CH3)2 and the HC---CH bonds, indicating that oxidation gives a quinoid-like species. The monocation illustrates an early step in the oxidation of p-phenylenediamine derivatives, which are widely used for hair dying. N,N-Dimethylphenylenediamine () also easily oxidizes to a radical cation, called Wurster's Red. The hydrochloride salt of TMPD has been used as a redox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
