Analogies can be powerful teaching tools because they can make abstract material intelligible to students by comparing it to material with which the students are already familiar. In this study, the authors interviewed 43 students to determine the specific ways they use analogies to learn and function in their biochemistry classes. They found that students use analogies in a variety of unique ways to promote understanding, visualization, recall, and motivation in their biochemistry clases. However, their uses of analogies did not always correlate well with their instructors' purposes for using analogies. They also discuss the teaching implications of these findings.