|MadSci Network: Biochemistry|
The archives response I believe you are referring to (876505725.Bc) noted the pH optimum for beef catalase. Unfortunately, I have not been able to track down a reference for the pH optimum of potato catalase - quite surprising given the popularity of this enzyme in teaching lab experiments. The pH optimum for a plant catalase such as potato may very well be different, and could depend upon other factors in the assay such as the type of buffer used, the ionic strength, etc. A few references for bacterial catalases I found did cite a wide range of pH optima. So I'm not surprized that you find a pH optimum for potato catalase that is different from 7.0!
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