Cell membrane transport is an important topic discussed in the biology classroom from the middle school to the graduate level. Membrane transport is complex, and students are often confused between different types of transport mechanisms. Dramatization is an active-learning strategy to engage students in learning. The flipped teaching method is designed to introduce lecture content prior to class meeting, thus creating time during class to adapt active-learning strategies such as dramatization. In this work, students were given a pretest prior to the dramatization activity. As each type of membrane transport was discussed, which included simple diffusion, osmosis, facilitated diffusion, and active transport, students were assigned specific roles to demonstrate the movement. The dramatization activity triggered many questions related to the topic, and these questions were addressed immediately. A posttest was conducted at the end of the dramatization activity. Our results demonstrated increases in the students’ understanding, engagement, and confidence level. The combination of flipped teaching and dramatization thus serves as a student-centered active-learning strategy for teaching difficult biological concepts.