Notizen: Untersuchungen zur lichtabhängigen Phosphorylierung VIII Über den Einfluß von 2.4-Dinitrophenol bei Ankistrodesmus braunii

Abstract

A partial separation of light-dependent from oxidative phosphorylation within a relatively small range of concentrations from 0.5 to 5 [center dot] 10-6 [image] dinitrophenol (DNP) was found to be possible. Results show that, in vivo also, light-dependent phosphorylation, at least part of the process, is hardly at all inhibited by definite concentrations of DNP which in darkness strongly inhibit oxidative phosphorylation. This is further proof that light-dependent phosphorylation in vivo is not the same as oxidative phosphorylation occurring in respiration but is an independent process following a different course. If it is permissible to transfer the results of investigations of photosynthetic phosphorylation, in isolated chloroplasts, in the form proposed by Arnon, to the relations in vivo, the relative DNP insensitivity of light-dependent phosphorylation here found indicates that, in vivo also, the cyclic phosphorylation of Arnon plays an important role.