This report describes a laboratory experiment for an undergraduate-level inorganic chemistry or biochemistry course involving the study of the kinetics of the catecholase activity of a synthetic nickel­(II)-oximate complex. A model substrate, 3,5-di-tert-butylcatechol(DBC), undergoes aerobic oxidation to 3,5-di-tert-butylbenzoquinone (DBQ) in the reaction. Students determine the initial rates of production of DBQ, measured by the increase of the absorption in the UV-vis spectrum at 400 nm; this was performed for solutions containing five separate substrate-to-catalyst ratios. Saturation kinetics was observed at high substrate-to-catalyst ratios, and the Michaelis-Menten model of enzymatic kinetics was applied to determine the kinetic parameters for the catalyst (k[subscript cat], V[subscript max], and K[subscript m]). Students explored the ability of two antioxidants, L-glutathione and [alpha]-tocopherol, to inhibit the oxidation reaction. The experiment has been employed at a small, four-year college in the Inorganic Chemistry course for three semesters. The experiment successfully provided students with a hands-on experience of using spectroscopy to monitor the kinetics of an enzyme-like system, including producing relevant plots and data analysis of Michaelis-Menten kinetic parameters. Students also examined the effects and roles of antioxidants in biochemical systems.