Re: How does the concentration of hydrogen peroxide affect the reaction...

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!