SSM-based electrophysiology helps to understand the mechanisms of different transporters. The technique was used to characterize and compare different sugar transporters and their transport deficient mutants. Proton-coupled (LacY, XylE, FucP), sodium-coupled (MelB) and loosely coupled (GlcP) sugar transporters were analyzed. A general transport model was concluded from the electrophysiological data. Here we present the most intriguing results for these transporters as well as our conclusions regarding the transport mechanism. We will discuss (1) substrate specifity, (2) protonation and coupling mechanisms, (3) the impact of different driving forces, (4) sugar binding kinetics and (5) the significance of specific amino acids for the transport cycle. All together SSM-based electrophysiology helped to conclude a detailed kinetic model for sugar transporters.