Why are physicists interested in biological membranes?
One good reason is that biological membranes have amazing physical properties. Biomembranes are soft materials, meaning they can deform and thermally fluctuate, while keeping their average structure stable. Many physicists are interested in describing these properties quantitatively based on physical principles such as the ones at the foundation of thermodynamics. In fact, biomembranes belong to the general class of liquid crystalline matter together with the "liquid" material used for digital displays (LCDs). An objective observer soon discovers that the biological material is an integral part of our physical universe. Although we might never need to build a stadium display from mitochondrial membranes, our learning experience can gain from constantly testing the limits of physical laws. As soon as an old law breaks down, a new one emerges. Don't hold your breath, though! Physical laws do not spring anew each season. They are amazingly universal and resilient. For example, Newton's second law which says that F equals ma, still holds 400 years after it was formulated and it also holds on Mars! Do membranes obey F = ma?!