Photosynthesis 



389 



Fig. 4. Oxygen gas produced at constant 

 illumination with green light with a 

 small quantity of blue-green light added 

 (six-hour experiment). 



7 2 3 4 



HOURS ILLUMINATED - 



The photolyte derivative of carbonic acid is designated by an asterisk, in order 

 to distinguish it from the untransformed carbonic acid. Nothing in this reaction 

 sequence is theory. All has been found experimentally and measured in living 



Table 1. Quantum requirement in 23 consecutive experiments 

 (mole quanta absorbed by Chlorophyll mole O2 developed). 



* This was the Single instance of a poor yield. 



Chlorella. Reaction 1, the light reaction, is measured by the 2 development and 

 CO2 consumption in the light. Reaction 2 is measured by the 0> consumption and 

 C0 2 production in the dark. Reaction 3, in which the bound, inactive carbonic 

 acid is transformed into the photolyte, is measured by the time that elapses until 

 the light is again able to develop as much 0> as in reaction 1. In our expenmental 

 arrangement this recovery period for füll light action lasted about 20 minutes, and 

 could therefore be followed very accurately in its time course. 



The photolyte is written as a Chlorophyll Compound because the quantity of 

 Oi that the light can develop from the photolyte is equivalent to the Chlorophyll 

 content of the cells'\ This is important. We now no longer have any need to wonder 

 how it is possible that the light energy is transferred without loss from the chloro- 



