148 



PROBLEMS OF PHOTOSYNTHESIS 



+ + 



O 





t 



OJ 



(f)-(D 



T. X 

 CO (f) 



X Sr 



/••-Q 



o 



o 



(X)- 

 ■ — \ 



CO 



/ 



o 



o 

 > 



Q. 





■a 



-I-' 



o 



3 



c 

 _o 



Si 



C 

 03 



(U 



C 



o 



c 

 o 



o 



a; 



C 

 >- 



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XJ 



Q. 

 15 



C 



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in 



LTl 



The following reaction is supposed to proceed on the positive side 



2 H.O -^ H2O2 + 2 H+ + 2 e 



In fact, this reaction corresponds to a potential of 1 .2 volt. The H2O2 pro- 

 duced may react with cytochrome f 



2Fe-'+ + HoOo -^ 2 Yc'+ + HoO + 0-- 



The Calvin scheme and its connections with respiration are shown in Figure 

 55. Calvin's views are intriguing but they are based upon quite a number 

 of pure hypotheses needing further experimental evidence. 



