Answer:
Enzyme pH levels also change the shape of the active site and affect the rate of enzyme activity. Each enzyme has its own optimal range of pH in which it works most effectively. In humans, catalase works only between pH 7 and pH 11. If the pH level is lower than 7 or higher than 11, the enzyme becomes denatured and loses its structure. The liver sustains a neutral pH of about 7, which creates the best environment for catalase and other enzymes.