Configuration of the light induced electric field in thylakoid and its possible role in the kinetics of the 515 nm absorbance chance

Theoretical calculations of the electric potential were carried out using a model of the thylakoid consisting of a spherical dielectric membrane surrounded both inside and outside by highly conductive material. The calculations yielded typical configurations and intensities of the electrical field induced by charges either localized in the membrane or delocalized in the conductive phases. It is shown that the build-up of the uniform transmembrane field is strictly correlated with translocation of charges from the membrane onto the boundaries of the conductive phases which induces a considerable increment in the field-intensity over the greater part of the thylakoid. This shows that the slow rise of the electrochromic absorbance change may be physically related to the slow translocation of charges from the membrane into the conductive phases which is linked to rate-limiting electron transport processes.