Introductory Chemistry laboratories must go beyond "cookbook" methods to illustrate how chemistry concepts apply to complex, real-world problems. In our case, we are preparing students to use their chemistry knowledge in the healthcare profession. The experiment described here explicitly models three important chemical concepts: dialysis of small molecules (dye), reversible binding (dye binding to albumin), and competitive binding (dye and a competitor binding to albumin). Moreover, each concept is intimately related to a physiological phenomenon: dialysis is used to treat renal failure, drugs travel in the blood bound to albumin, and competitive albumin binding is a common drug-drug interaction. In the context of this simple series of experiments, students create models, use evidence to validate their models, and finally use their understanding to describe physiological phenomena. This laboratory experiment was implemented in a 100-level course for predominantly prenursing majors. Student pre- and postlab models were examined, illustrating an improved conceptual understanding upon performing the lab and use of evidence to improve or support models. This experiment can be performed in 1 h, and can be adapted as a lecture demonstration.