Electric Field and Chloroplast Membranes
During green plant photosynthesis not all of the energy of the light absorbed by chlorophyll is used. A part, 2–3%, is re-emitted as fluorescence. A somewhat smaller part that we call delayed light is emitted at times of 10−5 sec to 3 hr after illumination, far too long to be fluorescence (1). This delayed light is closely connected with the process of photosynthesis and seems to be one of the few ways of studying the first steps in that process (2). While making such studies with “broken” chloroplasts, we observed that the delayed light could be stimulated by an electric field across the chloroplast suspension. This new effect is surprisingly large. A field of a few hundred volts/cm can increase the light emission by 50 times. We made a preliminary announcement of this phenomenon at the International Conference on the Photosynthetic Unit, held in Gatlinburg a year ago (3).
KeywordsApplied Electric Field Electrical Effect Chloroplast Membrane Trap Hole Electron Volt
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