|MadSci Network: Biochemistry|
Hello, Edgella -- your question took me back to my master's thesis (I worked on developing a glucose sensor, involving glucose oxidase and catalase)......anyway, to answer your question: The rate of the catalase reaction follows one of the general equations for enzyme-catalyzed reactions, the Michaelis-Menten equation. The rate of the catalase reaction with hydrogen peroxide would be: reaction rate V = Vmax x [Concentration of hydrogen peroxide] ------------------------------------------- Km + [Concentration of hydrogen peroxide] Vmax is the maximum reaction rate. Km is the Michaelis-Menten constant, and for catalase, Km = 25mM (25 millimoles/liter). Basically, the Michaelis-Menten equation reflects the fact that the reaction rates for enzymic reactions saturate -- that is, they reach a maximum reaction rate (Vmax), and stay at that maximum reaction rate regardless of how much additional hydrogen peroxide you add beyond that point. You should be able to plot what this graph should look like, for various amounts of hydrogen peroxide -- hopefully, the time that the disc takes to rise from the bottom of a beaker full of various concentrations of hydrogen peroxide should correspond to the reaction time, and therefore with the reaction rates. Good luck! And happy experimenting!
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