20 : 7/ Photosynthesis 379 



enzymes and the carbon cycle. The entire reaction has a very high 

 efficiency; 30 to 60 per cent of the photon energy absorbed is used to 

 produce carbohydrate and oxygen. 



The study of photosynthesis is in a state of transition. In the not too 

 distant past, standard histological techniques and simple chemical pro- 

 cedures were used to reveal many of the basic characteristics of photo- 

 synthesis. More recently, highly specialized chemical and physical 

 tools have become an essential part of photosynthetic studies. It 

 appears that the outstanding advances of the future will involve the 

 application of physical techniques such as the X-ray determination of 

 molecular structure and arrangement. 



REFERENCES 



The number of books and articles on photosynthesis is very large. Owing, 

 however, to the rapid advances in this field, many of these become outdated 

 very rapidly. This applies especially to the interpretation, on the molecular 

 level, of the mechanism of photosynthesis. The following selections should 

 be helpful to readers interested in more detailed discussions of photosynthesis 

 than it was possible to include within the limits of this text. 



1. Calvin, Melvin, "Energy Reception and Transfer in Photosynthesis," 

 Rev. Mod. Phys. 31: 147-156 (Jan. 1959). 



a. "Free Radicals in Photosynthetic Systems," pp. 157-161. 



2. Kasha, Michael, "Relation Between Exciton Bands and Conduction Bands 

 in Molecular Lamellar Systems," Rev. Mod. Phys. 31: 162-169 (Jan. 1959). 



To understand the previous article it is helpful to read : 



a. Livingston, Robert, " Intermolecular Transfer of Electronic Excita- 

 tion," J. Phys. Chem. 61: 860-864 (July 1957). 



b. Rabinowitch, E., " Photosynthesis and Energy Transfer," J. Phys. 

 Chem. 61: 870-878 (July 1957). 



3. Gaffron, Hans, et al., ed., Research in Photosynthesis (New York: Interscience 

 Publishers, Inc., 1957). An advanced text of transient interest. 



4. Arnon, D. I., "Localization of Photosynthesis in Chloroplasts," The 

 Enzymes: Units of Biological Structure and Function, Gaebler, O. H., ed. (New 

 York: Academic Press, Inc., 1956). 



5. Bassham, J. A., and Melvin Calvin, Path of Carbon in Photosynthesis (Engle- 

 wood Cliffs, N.J.: Prentice-Hall, Inc., 1957). 



Extremely complete compendia replete with references : 



6. Rabinowitch, E. I., Photosynthesis and Related Processes. Vol. I. Chemistry 

 of Photosynthesis, Chemo synthesis and Related Processes In Vitro and In Vivo 

 (New York: Interscience Publishers, Inc., 1945). 



a. Spectroscopy and Fluorescence of Photosynthetic Pigments: Kinetics of Photo- 

 synthesis. Vol. II, Part I (New York: Interscience Publishers, Inc., 

 1951) pp. 603-1208. 



b. Kinetics of Photosynthesis (cont.). Vol. II, Part II. Addenda to 

 Vol. I and Vol. II, Part I (New York: Interscience Publishers, Inc., 

 1956) pp. 1211-2088. 



