The Thermodynamic and Kinetic Limits on the Process of Free Energy Storage by Photosynthetic Systems*

where TR (v) is the radiation temperature introduced by Planck2 in order to describe the nonequilibrium radiaHon, and T is the working system temperature. The kinetic arrangements for free energy storage are completely ignored in (1). The simplest known photosynthetic mechanism developed by nature is based on the action of protein bacteriorhodopsin, which was isolated from purple membrane patches of Halobacterium halobium.3 Upon illumination the light absorbing pigment: retinal, goes through the cycle of conformational ,changes concomitant with such changes of the opsin part of bacteriorhodopsin, with net result that protons are ejected from archaebacteria. Since proton -electrochemical gradient is created at the expense of photon free energy bacteriiorhodopsin acts as free energy converter rather than quantum detector like his cousin rhodopsin which is involved in the process of vision.