A Quick and Accurate Oxygen-Based Pressure-Sensor Assay for Catalase Activity

A method is described for investigating the catalytic decomposition of hydrogen peroxide by using a computer-interfaced pressure sensor to follow the evolution of O₂(g) inside a closed reaction vessel. The pressure sensor and accompanying glassware are readily available in many chemistry labs or can be obtained at a relatively low cost. The method is particularly suited for kinetic studies of the enzymatic action of catalase on H₂O₂, which is known to follow the Michaelis–Menton mechanism. Appropriate for use with undergraduate chemistry students in physical chemistry or biochemistry, the data collection and analysis can be accomplished in one three-hour lab meeting. In comparison to other methods that have been recommended for catalase–H₂O₂ studies, the electronic pressure-sensor approach offers a number of advantages that allow for a reliable determination of the Michaelis–Menton constant in this system.