Most of the cellular processes are executed by sets of proteins that work like molecular machines in a coordinated manner, thus acting like an assembly line and making the process a more efficient one. One of such assembly lines is the one formed by molecular chaperones, a group of proteins involved in cell homeostasis through two opposite functions, protein folding and degradation. Over the last years it has been found that chaperones are not only devoted to assisting the folding of other proteins, but also given the right conditions and the presence, they can be active players in protein degradation. The two processes are carried out through the transient formation of complexes between different chaperones and co-chaperones. Our goal is the structural characterization of some of these complexes, using as a main tool electron microscopy and image processing techniques, and combining the information obtained with the available atomic structures of some of these chaperones and co-chaperones, with the aim of understanding the structural mechanisms by which these complexes function. Another objective is to characterize, for some of these chaperones, the forces involved in their activity, using the novel technique of optical tweezers.