Michaelis-Menten Synthesis

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An enzyme can be defined as a protein that acts as a catalyst in a biological system. It increases the rate of reaction by decreasing the activation energy. The catalytic power and specificity of an enzyme can be altered by the binding of certain molecules. These molecules are referred to as inhibitors. An inhibitor works to prevent the formation, or to cause the breakdown of an enzyme-substrate compound. There are two categories of inhibitors. The first being irreversible inhibitors, and the second being reversible inhibitors. Irreversible inhibitors tend to be more tightly bound, covalently or noncovalently (mostly covalently), to the enzyme than reversible inhibitors, which tend to dissociate more rapidly from the enzyme. Reversible inhibitors can be subdivided into three groups: competitive, uncompetitive, and noncompetitive. Competitive inhibition occurs whenever the inhibitor (which resembles the substrate) binds at the active site of an enzyme. The inhibitor positioning itself at the active site, blocks the chance of a substrate binding to the active site of the enzyme. The binding of a competitive inhibitor to the active site, reduces the …show more content…

On a Michaelis-Menten plot, the presence of a competitive inhibitor results in a change of the Km value, but not the Vmax value. With an Uncompetitive inhibitor both the Km and the Vmax are decreased. A Noncompetitive inhibitor decreases the value of Vmax, but doesn’t affect Km. The Lineweaver-Burk plot is the reciprocal of the Michaelis-Menten plot. A competitive inhibitor affects a Lineweaver-Burk plot by causing a right shift in the x-axis. With an uncompetitive inhibitor, the shift occurs along both the x-axis and y-axis. The x-axis is shifted to the left, and the y-axis is shift up. A noncompetitive inhibitor on a Lineweaver-Burk plot will have a slope that in shifted higher along the

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