A force spectroscopy model experiment is presented using a low-cost tensile apparatus described earlier. Force-extension measurements of twisted rubber bands are obtained. They exhibit a complex nonlinear elastic behaviour that resembles atomic force spectroscopy investigations of molecules of titin, a muscle protein. The model experiments open up intriguing possibilities to stimulate insight into entropy-driven self-organization of soft biological matter at the nanometre scale and into protein folding by hands-on experience and analogical transfer. (Contains 4 figures.)