An inexpensive 2-D and 3-D model of the sarcomere as a teaching aid

To address a common problem of teaching the sliding filament theory (that is, students have difficulty in visualizing how the component proteins of the sarcomere differ, how they organize themselves into a single working unit, and how they function in relation to each other), we have devised a simple model, with inexpensive materials, to be built by students in the fourth year of an undergraduate biology course. This model can be quickly built by the students themselves and is functional enough to allow visualization of the filaments and their properties. The model uses cheap, simple materials, mostly party and craft supplies, to simulate the component proteins of the sarcomere, and the proposed materials can be readily replaced by more available ones.