Laboratory exercises, which utilize alkaline phosphatase as a model enzyme, have been developed and used extensively in undergraduate biochemistry courses to illustrate enzyme steady-state kinetics. A bioinformatics laboratory exercise for the biochemistry laboratory, which complements the traditional alkaline phosphatase kinetics exercise, was developed and implemented. In this exercise, students examine the structure of alkaline phosphatase using the free, on-line bioinformatics protein-modeling program Protein Explorer. Specifically, students examine the active site residues of alkaline phosphatase and propose functions for these residues. Furthermore, by examining the mechanism of alkaline phosphatase and by using the published kinetic data, students propose specific roles for several active-site residues. Paired t-test analysis of pre- versus postexercise assessment data shows that the completion of the exercise improves student's ability to use kinetic data correctly thereby determining a probable catalytic function for an active site amino acid. (Contains 4 figures and 1 table.)