332 PHOTOSYNTHESIS 



claimed that it is possible to synthesize sugars from carbon dioxide and water 

 under the influence of certain wave lengths of light, an active form of 

 formaldehyde being postulated as an intermediate product. Since several in- 

 vestigators who have tried to duplicate this work have not been able to confirm 

 Baly's results the validity of these conclusions seems in doubt. 



5. Theory of JVillstiitter and Stoll. — The theory proposed by these two 

 investigators (191 8) may be cited as an example of one of several which 

 attempts to reconcile the foiTnaldehyde theory of photosynthesis with known 

 physiological facts.^ According to this hypothesis the first step in the process 

 is the combination of a carbonic acid molecule with the magnesium atom of 

 a chlorophyll molecule, forming "chlorophyll-bicarbonate": 



» R< ^^Mg— O — Cr^ 



<"'" OH 



\> NH 



Chlorophyll bicarbonate 



The next step in the process is supposed to be a photochemical intramolec- 

 ular shift in the atoms of the chlorophyll-bicarbonate complex resulting in 

 the production of "chlorophyll-formaldehyde peroxide," a compound of higher 

 energy content : 



^5nH "^^ \>NH 



Chlorophyll bicarbonate Chlorophyll-formaldehyde-peroxide 



Following this reaction the chlorophyll-formaldehyde-peroxide is supposed 

 to be split by an enzyme with chlorophyll, formaldehyde, and oxygen as the 

 cleavage products: 



^>N^ HO 



- ^ ' ^^ I enzyme 

 R< ,^>Mk— 0— CC ^— ^R 



.5nh 



Chlorophyll -formaldehyde-peroxide Chlorophyll 



3 An elaboration of this theory has been proposed by Stoll (1932). 



