28 



B. Rumberg, P. Schmidt-Mende , J. Weikard and H.T. Witt 



Fig. 1. Spectra of flash induced absorption changes in suspens- 

 ions of normal (top) and petroleum ether extracted chloroplast 

 (bottom) from spinach. pH = 7,2; 2o°C. 



Fig. 2. Spectra of the light induced irreversible absorption 

 changes in spinach chloroplast fragments at -15o C in the absen- 

 ce (top) and in the presence of red PMS (bottom). 



Fig. 3. Half-life of the absorption changes at 435 mu agd 7o5 niu 

 in aged whole spinach chloroplasts as function of pH. 2o C, ad- 

 ditions: 1o~5 M/1 PMS and 3.1o~5 M/1 ascorbate. 



Fip;. 4. Log. plot of the relative absorption changes at 7o5 mu 

 in aged whole spinach chloroplasts vs. time at different PMg 

 concentrations (+3.1o~5 M/1 ascorbatein excess). pH = 8, 2o C. 



Fi g . 5 . Bottom: Time course of the absorption changes at 7o5 mu 

 in chlorella cells induced by short flash (-'1o~ sec) of red 

 light at t = 0. a' in soft and b' in medium measuring light. 

 2o C, pH = 7,8. For further details see text. 



Fig. 6. Time course of the absorption changes at 7o5 mu in wholB 

 spinach chloroplasts without additions (top) and with added ben- 

 zyl viologenec-as e-acceptor (bottom). 2o C, pH = 7,2. The light 

 flash ( 1o~ sec) was turned on at t = 0. 



Fig. 7' Time course of the absorption changes at 7o5 mu and 430 

 mu in whole spinach chloroplasts in the presence of 1o~ M/1 

 benzyl viologene with soft measuring light and continuous 

 7I0 mu background light. 2o C, pH = 7,2. Both absorption changes 

 were induced by a flash ( — 1o~5 sec) at t = 0. 



Fig. 8. Time course of the absorption changes at 7o5 mu in whole 

 spinach chloroplasts in the absence and in the presence of CI.1U 

 and cm plus benzylviologene . 2o°C, pH = 7,2. The flash (--1o"5 

 sec) was turned on at t = 0. 



Fig. 9» Redox titration of the photo-induced absorption changes 

 at 7o5 niu in aged spinach chloroplast fragments. Log. plot of 

 (4 Imax -JI)/4I vs. the redox potential of added f erri-/ferrocya- 

 nide mixtures at different pH-values of t^e suspension. Ferri- + 

 ferrocyanide concentration =»■ 1o~2 M/1, 2o C. 



Fig.lo . Scheme of reaction cyclus 1 (left) and of reaction cyc- 

 lus II (right). For details see text. 



Fig. 11 . Spectra of the flash-induced absorption changes in spi- 

 nach chloroplast fragments in the absence (top) and in the pre- 

 sence (bottom) of 1o-^ M/1 DFIP plus 1o~^ M/1 ferricyanide . 2o C, 

 pH = 7,2. 



Fig. 12. Spectra of the absorption changes in spinach chloroplast 

 fragments under normal condition, after extraction with petroleum 

 ether and after recondensation of plastoquinone . (1) soft, (2) 

 medium, and (3) strong extraction. 2o C, pH = 7,2. 



Fig. 13. Time course of the absorption changes at 515 mu and 254 

 mu in spinach chloroplast fragments under normal condition (top), 

 after partial extraction with petroleum ether (middle) and after 

 recondensation of plastoquinone (bottom). 2o C, pH = 7,2. The 

 flash (~'2.1o~'^ sec) was turned on at t = 0. 



