For this experiment, we used store-bought potatoes that were prepared ahead of time by chopping them into 3 roughly equal portions, freezing one portion by placing it in a -20℃ freezer, boiling one portion, and leaving one portion at room temperature. Just before the experiment/demonstration, potatoes were taken out of the freezer or the hot water bath. Each type of potato was added to 3 different beakers containing ~10 mL of 3-12% hydrogen peroxide (CVS). Catalase in the potatoes reacts with H2O2 to produce O2 that fizzles out of the solution and is observable by the naked eye (Figure ). As expected, the enzymatic reaction is the fastest at room temperature (22 ⁰C) and students observe maximum fizz, while catalase in the frozen potatoes is slowed down and exhibits lesser fizz. On the other hand, boiled potatoes contain unfolded catalase enzyme that is unable to catalyze the reaction and produces no fizz.