Many undergraduates struggle to interpret abstract concepts in molecular biology. Modeling can facilitate learning by making these abstract concepts tangible. Here, we present an exercise based on the lac operon designed for undergraduate students using LEGO bricks. The lac operon is a classic example of transcriptional regulation taught in a variety of undergraduate biology courses and is fundamental to understanding the regulation of gene expression. This easy-to-implement active learning exercise demonstrates how the various components of the lac operon are oriented under a variety of nutritional conditions to control gene expression. In addition, higher-order concepts, such as the effect of mutation on lac operon expression, can be readily modeled. Overall, students not only found this exercise to be enjoyable but also helpful as a tool to engage with this course material.
Keywords: LEGO; STEM education; catabolite repression; gene regulation; in-class activity; lac operon; student-centered.