Open AccessEnergy‐Dependent Reverse Electron Flow in Chloroplasts
Author(s) -
Rienits Keith G.,
Hardt Haim,
Avron Mordhay
Publication year - 1974
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1974.tb03412.x
Subject(s) - electron transport chain , redox , electron transfer , electron flow , photochemistry , chloroplast , chemistry , biophysics , cytochrome , cytochrome c , dcmu , cytochrome f , fluorescence , cytochrome b6f complex , coupling (piping) , photosynthesis , mitochondrion , biochemistry , biology , materials science , inorganic chemistry , enzyme , physics , thylakoid , quantum mechanics , metallurgy , gene
An ATP‐driven rise in fluorescence yield (Q reduction) and cytochrome f oxidation in light‐triggered chloroplasts are demonstrated. Both effects are shown to be dependent on the creation and maintenance of the light‐triggered state. ATP‐induced reduction of Q depends upon the presence of an electron donor in the dark with a redox potential up to, but not exceeding, 300 mV. The effects are abolished by uncouplers or energy transfer inhibitors. 3‐(3,4‐Dichlorophenyl)‐1,1‐dimethylurea inhibits the ATP‐driven reduction of Q but not that of cytochrome oxidation. A location for a coupling site and the site of action of electron‐transport inhibitors is suggested on the basis of these observations.