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Inexpensive lab activities


The cell membrane is a ubiquitous component in mammalian cells which control many vital biological functions. It consists of a phospholipid bilayer with embedded protein molecules which serve to transport molecules between the interior and exterior of the cell. Understanding what makes cell membranes so important and how they function requires concepts from physics, chemistry, and of course biology, but it is difficult to learn and conceptualize the structure and function of membranes due to their nanoscopic size and dynamic nature which can’t be properly appreciated in a static textbook. This activity draws analogies between the chemistry and structure of soap films, which are essentially the inverse of the cell membrane, to create a macroscopic model that illustrates many important concepts in biology. Concepts emphasized include membrane fluidity, flexibility, amphiphilicity, passive/active transport, and membrane fusion/division processes. Using materials entirely available at a grocery store, students explore cell membrane structure and function using the more tangible and accessible soap film.