Subject: How does conc. of Hydrogen Peroxide affect the IMMOBILIZED enzyme catalase?

I have recently conducted several experiemnts as part of my coursework. 
The aim of my investigation is to find out how changing the conc. of H2O2 
affects the rate of reaction (immobilized catalase) The enzyme is trapped 
in beads made from sodium aliginate. My results show that increasing the 
conc. from 5 volume to 20 volumes of H2O2 has no effect on the rate of 
reaction. I thought that maybe the reaction was zeroth order with respect 
to H2O2, but later thought that it may be that I am not using enough 
enzyme (therefore not enough active sites) for the conc. I selected. Could 
you tell me what should happen? and why I obtained the results I did?

Re: How does conc. of Hydrogen Peroxide affect the IMMOBILIZED enzyme catalase?