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R max and K m (26.4). Constants from Michaelis-Menten equation give insight into qualitative and quantitative aspects of enzyme kinetics Indicate if enzyme inhibition is present and what type of inhibition is exhibited
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Rmax and Km (26.4) • Constants from Michaelis-Menten equation give insight into qualitative and quantitative aspects of enzyme kinetics • Indicate if enzyme inhibition is present and what type of inhibition is exhibited • Rmax is the maximum possible rate of conversion of substrate to product for a given enzyme • Km is related to how tightly an enzyme binds a substrate (the higher the value, the less tightly bound the substrate) • Inverting the Michaelis-Menten rate law gives an equation that can be useful for obtaining the maximum rate and the Michaelis constant • Lineweaver-Burk plot is generated by plotting 1/rate vs. 1/[S] • Lineweaver-Burk equation is more useful for getting constants since experiments can be done over a short range of substrate concentrations • y-intercept gives us Rmax, which is then used with the slope to get Km
Enzyme Inhibition (26.4) • Inhibition is a term used to describe the inability of a product being formed due to the presence of another substance (the inhibitor) • Enzyme inhibition can be competitive or noncompetitive • Competitive inhibition is caused when an inhibitor “competes” with the substrate in binding with the enzyme • Inhibitor decreases production of ES, thus decreasing product formation • Noncompetitive inhibition is caused when an inhibitor can bind to either the free enzyme or the enzyme-substrate complex • Inhibitor does not allow ES complex to convert to products
Michaelis-Menten Plot for Catalyzed Reaction of CO2 with H2O