Temperature dependence of chlorophyll a fluorescence in relation to the physical phase of membrane lipids algae and higher plants

The temperature dependence of the yield of chlorophyll a fluorescence was measured at room temperatures in living algal cells and higher plant chloroplasts. 3-(3′,4′-Dichlorophenyl)-1, 1-dimethylurea was added to the samples during the measurements in order to eliminate the influence of photosynthetic photochemical reactions on the fluorescence yield.