Activation Spectra of 700 mμ Absorption Change in Photosynthesis

Abstract

Activation spectra were measured of the light induced absorption changes at 700 mu in photosynthetic organisms. The direct photochemical bleaching of the involved pigment appeared to be sensitized mainly by chlorophyll a and possibly carotenoids. The opposite effect, accelerated restoration of this pigment, was sensitized mainly via accessory pigment (such as phycocyanin in Anacystis) and mediated by dark reaction steps. The data suggest that both light reactions are functionally involved in photosynthesis.