Use of a Short, In-Class Drawing Activity to Assess Student Understanding of Core Concepts of the Cell Membrane in an Undergraduate Physiology Course

Students in an animal physiology course are required to have completed prerequisite cell biology and genetics courses that include discussion of basic properties and functions of the cell membrane. However, while many students remember basic information about membrane structure, they often have difficulty relating that structure to membrane functions, such as vesicular transport, active transport, osmosis, and current flow across the membrane. To better understand what students recall about the cell membrane, students were given an open-ended prompt to draw what they know about the structure and function of the animal cell membrane. This activity was repeated 1-2 weeks after finishing discussion of the cell membrane in class, with an emphasis on the concepts of membrane transport and a related core concept, flow along gradients. Student responses were analyzed using the conceptual framework for the "cell membrane" core concept published by Michael and Modell (Michael J, Modell H. "Adv Physiol Educ" 43: 373-377, 2019). Before covering this content in class, the majority of submissions included a representation of the cell membrane as a phospholipid bilayer, and a high percentage also included membrane proteins or the fluid mosaic model. Similar percentages of students included these concepts in the postcoverage drawing. However, other components of the conceptual framework were included less frequently or not at all before covering the content in class but improved dramatically afterward. This activity provides information about what students recall from prior coursework and which concepts need to be revisited, and it can provide a complementary assessment of student understanding of the core concept of the cell membrane.