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Lineweaver–Burk Plot
In biochemistry, the Lineweaver–Burk plot (or double reciprocal plot) is a graphical representation of the Lineweaver–Burk equation of enzyme kinetics, described by Hans Lineweaver and Dean Burk in 1934. The Lineweaver–Burk plot for inhibited enzymes can be compared to no inhibitor to determine how the inhibitor is competing with the enzyme. The Lineweaver–Burk plot is correct when the enzyme kinetics obey ideal second-order kinetics, however non-linear regression is needed for systems that do not behave ideally. The double reciprocal plot distorts the error structure of the data, and is therefore not the most accurate tool for the determination of enzyme kinetic parameters. While the Lineweaver–Burk plot has historically been used for evaluation of the parameters, together with the alternative linear forms of the Michaelis–Menten equation such as the Hanes-Woolf plot or Eadie–Hofstee plot, all linearized forms of the Michaelis–Menten equation should be avoided ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michaelis Constant
Michaelis or Michelis is a surname. Notable people and characters with the surname include: * Adolf Michaelis, German classical scholar * Anthony R. Michaelis, German science writer * Edward Michelis, German theologian * Georg Michaelis, German politician * Gustav Adolf Michaelis, German obstetrician and namesake of the rhombus of Michaelis * Hans-Thorald Michaelis, German historian * Johann David Michaelis, German biblical scholar * John H. Michaelis, American four-star general * Laura Michaelis, American linguist * Leo Michelis, Greek-Canadian economist * Leonor Michaelis, German scientist known for Michaelis–Menten kinetics * Max Michaelis, South African financier * Margaret Michaelis-Sachs, Austrian-Australian photographer * Paul Charles Michaelis, American scientist * Peter Michaelis, German botanist * Robert Michaelis (1878–1965), French-born actor and singer who settled in England * Sebastian Michaelis, the demon butler from Kuroshitsuji * Sebastien Michaelis, Frenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hanes–Woolf Plot
In biochemistry, a Hanes–Woolf plot, Hanes plot, or plot of a/v against a, is a graphical representation of enzyme kinetics in which the ratio of the initial substrate concentration a to the reaction velocity v is plotted against a. It is based on the rearrangement of the Michaelis–Menten equation shown below: : = + where K_\mathrm is the Michaelis constant and V is the limiting rate. J B S Haldane stated, reiterating what he and K. G. Stern had written in their book, that this rearrangement was due to Barnet Woolf. However, it was just one of three transformations introduced by Woolf, who did not use it as the basis of a plot. There is therefore no strong reason for attaching his name to it. It was first published by C. S. Hanes, though he did not use it as plot either. Hanes said that the use of linear regression to determine kinetic parameters from this type of linear transformation is flawed, because it generates the best fit between observed and calculated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eadie–Hofstee Diagram
In biochemistry, an Eadie–Hofstee diagram (more usually called an Eadie–Hofstee plot) is a graphical representation of the Michaelis–Menten equation in enzyme kinetics. It has been known by various different names, including Eadie plot, Hofstee plot and Augustinsson plot. Attribution to Woolf is often omitted, because although Haldane and Stern credited Woolf with the underlying equation, it was just one of the three linear transformations of the Michaelis–Menten equation that they initially introduced. However, Haldane indicated latter that Woolf had indeed found the three linear forms: "''In 1932, Dr. Kurt Stern published a German translation of my book "Enzymes", with numerous additions to the English text. On pp. 119-120, I described some graphical methods, stating that they were due to my friend Dr. Barnett Woolf.'' ..''Woolf pointed out that linear graphs are obtained when v is plotted against v x^, v^ against x^, or v^x against x, the first plot being most convenien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uncompetitive Inhibition
Uncompetitive inhibition, also known as anti-competitive inhibition, takes place when an enzyme inhibitor binds only to the complex formed between the enzyme and the substrate (the E-S complex). Uncompetitive inhibition typically occurs in reactions with two or more substrates or products. While uncompetitive inhibition requires that an enzyme-substrate complex must be formed, non-competitive inhibition can occur with or without the substrate present. Uncompetitive inhibition is distinguished from competitive inhibition by two observations: first uncompetitive inhibition cannot be reversed by increasing and second, as shown, the Lineweaver–Burk plot yields parallel rather than intersecting lines. This behavior is found in the inhibition of acetylcholinesterase by tertiary amines (R3N). Such compounds bind to the enzyme in its various forms, but the acyl-intermediate-amine complex cannot break down into enzyme plus product. Mechanism As inhibitor binds, the amount of ES comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Competitive Inhibition
Competitive inhibition is interruption of a chemical pathway owing to one chemical substance inhibiting the effect of another by competing with it for binding or bonding. Any metabolic or chemical messenger system can potentially be affected by this principle, but several classes of competitive inhibition are especially important in biochemistry and medicine, including the competitive form of enzyme inhibition, the competitive form of receptor antagonism, the competitive form of antimetabolite activity, and the competitive form of poisoning (which can include any of the aforementioned types). Enzyme inhibition type In competitive inhibition of enzyme catalysis, binding of an inhibitor prevents binding of the target molecule of the enzyme, also known as the substrate. This is accomplished by blocking the binding site of the substrate – the active site – by some means. The Vmax indicates the maximum velocity of the reaction, while the Km is the amount of substrate needed to r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme Inhibition Lineweaver-burk Plots
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction rat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cartesian Coordinate System
A Cartesian coordinate system (, ) in a plane is a coordinate system that specifies each point uniquely by a pair of numerical coordinates, which are the signed distances to the point from two fixed perpendicular oriented lines, measured in the same unit of length. Each reference coordinate line is called a ''coordinate axis'' or just ''axis'' (plural ''axes'') of the system, and the point where they meet is its ''origin'', at ordered pair . The coordinates can also be defined as the positions of the perpendicular projections of the point onto the two axes, expressed as signed distances from the origin. One can use the same principle to specify the position of any point in three-dimensional space by three Cartesian coordinates, its signed distances to three mutually perpendicular planes (or, equivalently, by its perpendicular projection onto three mutually perpendicular lines). In general, ''n'' Cartesian coordinates (an element of real ''n''-space) specify the point in an ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biochemistry
Biochemistry or biological chemistry is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology and metabolism. Over the last decades of the 20th century, biochemistry has become successful at explaining living processes through these three disciplines. Almost all areas of the life sciences are being uncovered and developed through biochemical methodology and research. Voet (2005), p. 3. Biochemistry focuses on understanding the chemical basis which allows biological molecules to give rise to the processes that occur within living cells and between cells,Karp (2009), p. 2. in turn relating greatly to the understanding of tissues and organs, as well as organism structure and function.Miller (2012). p. 62. Biochemistry is closely related to molecular biology, which is the study of the molecular mechanisms of biological phenomena.As ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
