Working with enzymes--Where is lactose digested?

The first of these experiments is the evaluation by redox titration of the vitamin C content of fresh green peppers and peppers cooked by various methods, as originally described by Johnson (1) and modified by Deal and Pope (2). In this experiment, the students are exposed to laboratory techniques involving enzymes and they learn some of the basic principles of enzyme assays. Since the lab is actually an elementary pH assay, students discover the idea of optimum pH for enzyme activity, which can then be further developed in the classroom. Since our course is taught on a basic level, we have chosen a very narrow focus for this experiment; however, the techniques utilized lend themselves readily to more complex assays and kinetic studies of lactase such as investigations of optimum temperature, substrate specificity, and detailed kinetics.