In this guided inquiry experiment, students extract catecholase enzyme from apples to catalyze the oxidation of catechol. They follow the reaction using the UV--vis absorbance of the "p"-benzophenone produced to determine the Michaelis-Menten kinetic parameters. Students make selected experimental choices within a structured framework such as selecting the apple varietal, the pH of the reaction mixture, and the reaction inhibitor. The experiment has been tested at multiple universities in physical chemistry laboratory courses with both large and small enrollments. We describe the experiment and its implementation in both synchronously and asynchronously taught courses.