Primary Events, Energy Transfer, and Reactions in Photosynthetic Units: The Ratio between Delayed Light and Fluorescence Emitted by Chloroplasts

Electric fields of a few hundred volts per centimeter greatly stimulate the emission of delayed light from “broken” chloroplasts. At low intensities of exciting light the fluorescence of these chloroplasts is also stimulated by the electric field, but to a lesser extent. Assuming that the electric field has no effect on prompt fluorescence, and has the same effect on the delayed light emission during illumination as in the dark, we can determine the ratio of delayed light to fluorescence under steady-state illumination.