Typical biochemistry labs exploring basic enzyme activity rely on costly, time-consuming protein purification and rarely explore enzyme function in situ. Further, complex purification procedures leave little room for novelty in experimental design. Here we present an inquiry-driven laboratory exercise for biochemistry undergraduates and adaptations for a general education science course. Each student designs a unique experiment to test their hypothesis regarding the nature of avocado browning in a three-hour span. In the presence of oxygen, polyphenol oxidases (PPO) catalyze oxidation of phenolic compounds into quinones, the polymerization of which creates the visible browning of many cut fruits. Avocado fruit, a source of both enzyme and substrate, is a safe, low-cost vehicle for semi-quantitative experimentation. During the incubation, biochemistry students use the Protein Data Bank and primary literature to understand the structure-function relationship of PPO and other molecular components of the avocado. Non-major students discuss how pH, temperature, and substrate availability affect PPO. Visible browning pigments appear on a controllable time scale. Students can photograph results to create a figure to accompany semi-quantitative analysis of experimental results in a single lab period. Since avocados are familiar foods and select test reagents are generally recognized as safe, the optimal protocol investigated in the lab can be further applied to best practices in the kitchen in everyday life, promoting the transfer of knowledge learned in the classroom to practical environments.