BIBLIOGRAPHY TO CHAPTER 23 801 



Arnold and Oppenheimer (1950) broke blue-green algae, Chroococcus 

 by squeezing through a syringe {cf. chapter 35) and separated the phy- 

 cobilin chromoproteid from the chlorophyll chromoproteid by fractiona- 

 tion with ammonium sulfate. The phycobilin fraction, resuspended in 

 water, showed a fluorescence band at 620-655 m^t. An estimate of the 

 yield of fluorescence gave a value of about 20%. The yield of fluorescence 

 is much lower (about 1.5%) in living Chroococcus cells. It increases upon 

 grinding of the cells under water, even without the separation of the phy- 

 cobihn from chlorophyll (cf. chapter 24, page 816). This is interesting 

 because the blue-green algae contain no chloroplasts; therefore, the "cell 

 juice," obtained by their grinding, should not differ so strongly in its proper- 

 ties from the contents of the living cell, as do the products of mechanical 

 destruction of chloroplast-bearing green cells. Arnold and Oppenheimer 

 suggested that the approximately tenfold increase in the yield of fluores- 

 cence upon grinding could be a pure dilution effect: In live cells, close 

 proximity of the average phycobilin molecule to one or several chloi-ophyll 

 molecules, permits a highly efficient resonance transfer of excitation energy 

 from phycobilin to chlorophyll (accounting for a high quantum yield of 

 photosynthesis in light absorbed by the phycobilins; cf. chapter 30, section 

 6). This leads to quenching of phycobilin fluorescence and substitution 

 of the (less intense) sensitized chlorophyll fluorescence. Dilution de- 

 creases the rate of resonance transfer and thus preserves the fluorescence 

 of the phycobihns. 



Bibliography to Chapter 23 



Fluorescence of Pigments in Vitro 



A. Fluorescence of Chlorophyll in Vitro 



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 1852 Stokes, G. G., Trans. Roy. Sac. London, 1852, 463. 

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Wilschke, A., Z. wiss. Mikroskop., 31, 338. 

 1Q18 Willstatter, R., and StoU, A., Untersuchungen iiber die Assimilation der 

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1920 Stern, K., Ber. deut. botan. Ges., 38, 28. 



1921 Stern, K., Z. Botan., 13, 193. 



1926 Perrin, J., 2"^ congres chimie Solvay, Gauthiers-Villars, Paris, p. 322. 



1927 Noack, K., Biochem'z., 183, 135. 



Perrin, J., Compt. rend. acad. sci. Paris, 184, 1097. 



1929 Perrin, F., Ann. phys., 12, 169. 



1930 Dh6r6, C., Compt. rend., 192, 1496. 



1931 Kautsky, H., and Hirsch, A., Ber. deut. chem. Ges., 64, 2677. 



