EFFECT OF PHOTOSYNTHESIS ON RESPIRATION 



565 



Table 20.1 

 Aftereffects of Photosynthesis on Respiration 



•> First hour after the illumination period. 

 ^ Second hour after the illumination period. 



illumination, can be attributed to stimulated respiration. Part of this 

 absorption may be caused by oxidations in the photosynthetic mechanism, 

 analogous to those which were assumed (in Chapter 19) to be responsible 

 for the photautoxidation in intense light and under high oxygen pressure. 

 The components and intermediates of the photosynthetic apparatus may 

 well be capable not only of a photochemical, but also of a slow non- 

 photochemical autoxidation. 



The existence of autoxidizable intermediate products formed by 

 photochemical processes in the chlorophyll apparatus is demonstrated 

 by the aftereffects of photautoxidation (which obviously cannot produce 

 carbohydrates). Whether the photoxidation had been brought about by 



