OPTICAL ACTIVITY OF BIOL. MATERIAL 33 



SUMMARY 



1. Dissymmetric molecules are found in inorganic nature 

 where they have evidently no relation to life, but it is ques- 

 tionable whether life is possible without dissymmetric 

 molecules. 



2. In inorganic nature, the two forms of dissymmetric 

 molecules are always represented in equal concentrations 

 and the aggregate of molecules thus formed is symmetric 

 (racemic mixture). 3. Asymmetry of molecular aggre- 

 gates is a specific property of protoplasm and of living 

 systems. 



4. Primary constituents of protoplasm, such as the 

 amino-acids, the lecithins and the majority of the impor- 

 tant sugars are present in protoplasm in the form of only 

 one of the optical isomers: they are obligatorily asym- 

 metric. 5. In these substances, the sign of the optical 

 activity is not replaceable by the opposite sign. 6. The 

 primary constituents of protoplasm are structurally re- 

 lated to each other and form ''biological series" of optical 

 isomers. 



7. The secondary constituents of protoplasm which, 

 functionally, represent storage material or excreta are not 

 obligatorily asymmetric ; they are sometimes found in liv- 

 ing organisms in the racemic state. 8. The sign of their 

 optical activity is replaceable by the opposite sign, so that 

 one optical isomer is sometimes found in one species and 

 its antipode in another. 



9. The optical activity of mineral oil lends support to 

 the theory of its organic origin. 



BIBLIOGRAPHY 



ACKEKMANN, D., Advances in Modern Biol. (Russian), 4, 5, 1935. 



BARTELT, K., Abderh. Bioch. Handlex., 7, 266, 1910. 



BENDRAT, M., Planta, 7, 508, 1929. 



BENNET-CLARK, T., Ann. Rev. Biochem., 6, 579, 1937. 



BOYS, S. F., Proc. Eoij. Soc. A.. 144, 655, 1934. 



BRANKE, J. AND PARISHEV, J., Plants of the Maritime Region and their 



Volatile Oils. Vladivostok (in Russian), 1937. 

 BROWX, H. AND MORRIS, H., Journ. Chem. Soc, 63, 604, 1893. 

 CLOUGH, G. W., Journ. Chem. Sor., 113, 526, 1918. 



