Based on our torsional mechanism of ion translocation, energy transduction and energy storage in ATP synthase [Cuff. Sci. 75 (1998) 716]; [Curr. Sci. 77 (1999) 167]; [Curr. Sci. 78 (2000) 23]; [Biochem. Biophys. Res. Commun. 272 (2000) 629]; [FEBS Lett. 476 (2000) 113]; [Thermochim. Acta 378 (2001) 35], the molecular mechanism for rotation of the c-rotor and the subsequent rotation of the gamma-subunit and the epsilon-subunit has been proposed. The details of the elementary steps involved in ion translocation and energy conversion in the F-0 portion of ATP synthase have been provided. Electrostatic effects drive the rotation of the c-subunits in steps of 15degrees each during proton binding as well as unbinding. During the rotation of the c-rotor, the energy of the ion gradients is transiently stored as twist in the c-subunits, and finally as torsional strain in the gamma-subunit. The mechanism has been shown to be consistent with a general kinetic analysis of ATP synthesis by ATP synthase. The detailed molecular mechanism compels a paradigm shift from chemiosmotic dogma (where the membrane simply acts as an insulator and only energized aqueous media are permissible) towards a view where molecular interactions between ion and protein-in-the-membrane are critical for elementary steps involving transduction, storage and utilization of the energy of the ion gradients.