Catalase is an enzyme that is commonly found in plant and animal tissues. The function of the enzyme catalase is to break down the chemical hydrogen peroxide inside living cells. Because it is toxic, or poisonous, hydrogen peroxide would soon kill the cell if it were not removed or broken down immediately.
In this lab, the enzyme catalase will be compared to the catalyst manganese dioxide. Catalysts are similar to enzymes in that they speed up chemical reactions, but they are not specific for just one reaction.