The Cell Membrane: A Thought Experiment
June 20, 2010 in Teaching Resources
A number of years ago, I developed a method for teaching students about the basic structure of the cell membrane that has proven to be both enjoyable and memorable, and after receiving positive feedback upon sharing this activity with my friends at the Center for BioMolecular Modeling at the Milwaukee School of Engineering, I figured that it is time that a share it with a larger community of individuals.
Simply, the method is a ”thought experiment” in which students graphically hypothesize the arrangement of a collection of molecules unknown to them (phospholipids) in three sequential situations, in order to personally discover the self-assembly of phospholipids in generating a simplified cell membrane.
Once students have discovered this basic image of a cell for themselves it becomes easier for them to supplement it generating a more complex conception of the cell.
In fact, I usually draw an analogy between the cellular container and the test tubes and beakers used in chemistry. Student readily understand that cells, “as places where chemical reactions occur” require:
- a container (the goal of this series of thought experiments),
- reactants,
- points of entry and exit (the membrane and supplemental proteins),
- a solvent (the water inside this simple cell),
- catalysts as biological enzymes,
- energy,
- and a controlling region or some means of regulation.
A summary of the “thought experiment” follows but for those that want more details, including images, or would rather read offline, I have created a document explaining this Cell Membrane Thought Experiment.
