BIBLIOGRAPHY TO CHAPTER 33 1429 



and is deactivated thermally by a reaction (with the substrate of photosynthesis) the 

 yield of which is proportional to [Chl*]^ (this reaction leading to the final product of 

 photosynthesis: Chi + hv —^ Chi*, Chi* + substrate —* Chi + product). No explana- 

 tion was given for the occurrence of a square of concentration in both equations. In 

 addition Smith's theory disregards the main objections against all induction theories 

 based on the accumulation of thermal intermediates — the irreversible character of the 

 induction losses. 



Briggs (1933) discussed two forms of an "inhibitor theory" of induction. In the 

 first one, the inhibitor was assumed to be of the "narcotic" type, i. e., one which makes 

 the sensitizer unavailable for photosynthesis by settling down on it. In the second 

 theory, the inhibitor was assumed to be of the cyanide type, and to prevent the primary 

 photoproducts from stabilization by the poisoning of an enzyme. Briggs derived, for 

 these cases, equations representing the approach of photosynthesis to its final steady 

 rate; but our present knowledge of the complexity of the induction curves makes us 

 sceptical with regard to the value of all such theoretical functions, even if they were found 

 to fit several experimental curves. 



Some more recent experimental studies (Mehler, p. 1568; Gerretsen, p. 1588; 

 Arnon et al., p. 1537) drew attention to one additional possible source of "asymmetric" 

 induction-photoxidation of ascorbic acid reserves. This may precede the utilization of 

 water as reductant and delay the liberation of oxygen, while permitting carbon dioxide 

 reduction to start immediately. (Initial reduction of "substitute reductants," instead 

 of carbon dioxide, obviously must have the opposite effect, as repeatedly suggested 

 above.) 



Speaking in general, with the gradual clarification of the biochemistry of photo- 

 synthesis a tendency arises to inquire into the qualitative chemical sources of induction 

 phenomena instead of analj'zing the induction curves in terms of a minimum nmuber 

 of kinetic factors. This is inevitable and natural; but the considerable experimental 

 work and ingenuity of interpretation invested in the stud.y of induction kinetics (and 

 of the kinetics of photosynthesis in general) should not be considered as wasted (as 

 some biochemists may be inclined to believe). They are fundamental contributions to- 

 ward the general edifice of photosynthesis — and biochemistry in general — as an exact 

 science. 



Bibliography to Chapter 33 



Induction Phenomena 



A. Gas Exchange during the Induction Period 



1865 Boussaingault, J. B., Compt. rend., 61, 493, 605, 657. 



1887 Pringsheim, N., Sitzber. Akad. Wiss. Berlin, 1887, 763. 



1918 Osterhout, W. J. V., and Haas, A. R. C, /. Gen. Physiol, 1, 1. 



Willstatter, R., and StoU, A., Untersuchungen iiber die Assimilation der 

 Kohlensdure. Springer, Berlin. 

 1920 Warburg, 0., Biochem. Z., 103, 188. 

 1922 Kostychev, S. P., Ber. deut. botan. Ges., 39, 319. 



1929 Li, Tsi Tung, Ann. Botany, 43, 787. 



1930 Harder, R., Planta, 11, 263. 



1932 van der Paauvv, F., Rec. trav. botan. neerland., 29, 497. 



1933 Briggs, G. E., Proc. Roy. Soc. London, B113, 1. 

 Harder, R., Planta, 20, 699. 



