Liver Laboratory Background Hydrogen peroxide is a by-product of cell metabolism that is toxic to cells. Catalase is important because it promotes the decomposition of hydrogen peroxide (H2O2). Oxygen gas is a product of this reaction (2H2O2 (+ O2) and often indicates the speed of the reaction. Do temperature, acidity, and concentration have an effect on the catalase activity as measured by the oxygen production rate? The purpose of this experiment is to determine the effect of temperature, concentration, and acidity on catalase activity. For the independent variable of temperature, the three levels are 5°C, 22°C, and 37°C. Six trials at the 5°C and 10°C levels and 6 trials at the 22°C level are conducted. For the independent variable of concentration, the three levels are 100%, 50%, and 25%. Six trials at the 100% level, six trials at the 50% level, and six trials at the 25% level were conducted. The 100% concentration level was the control in this instance. For the independent variable of acidity, the three levels were pH levels of four, seven, and ten. Six trials for the level of a pH of four, 6 trials for the level of a pH of seven, and six trials for the level of the pH of ten were conducted. The level of a pH of seven is the control in this instance. The dependent variable is catalase activity. Catalase activity is measured by the rate of oxygen gas evolved in milliliters per thirty seconds.