SAPONIFIABLE LIPIDS 87 



3. The pathway of biosynthesis for the unsaturated fatty acids of higher plants is 

 still obscure. In yeast it is well established that saturated acids are directly 

 dehydrogenated to form the unsaturated ones (46), but in higher plants it ap- 

 pears that there may be separate pathways for the saturated and unsaturated 

 acids (47, 48). 



4. Phosphatidylserine is made by an exchange of serine for the ethanolamine 

 moiety of phosphatidylethanolamine. Phosphatidylserine can also be decarboxy- 

 lated directly to phosphatidylethanolamine. Phosphatidylethanolamine can be 

 directly methylated to form lecithin. Thus, interconversions of these three 

 types of phospholipids can occur without complete breakdown and resynthesis. 



5. Practically nothing is known regarding biosynthesis of the sphingolipids and 

 glycolipids although Benson et al. (16) have suggested that glycolipid sulfonic 

 acids may be made by the oxidative splitting of a disulfide. Photosynthe sizing 

 Chlorella fix labelled CO2 into glycolipids much more rapidly than into trigly- 

 cerides (49). 



6. The a-oxidation of long chain fatty acids seems to be a reaction peculiar to 

 higher plants and is catalyzed by a peroxidase in the presence of other enzyme 

 systems which can generate hydrogen peroxide. It is one way to account for the 

 occasional appearance of long chain aliphatic compounds with an odd number of 

 carbon atoms. See (50) for further details. 



GENERAL REFERENCES 



Cowan, J. C. and Carter, H. E. , "Lipids" in Organic Chemistry 3 178, H. Oilman ed. , 



John Wiley, N. Y. , 1953. 

 Deuel, H. J., The Lipids 3 vols. , Interscience Publishers, N. Y. , 1951-1957. 

 Ounstone, F. D. , An Introduction to the Chemistry of Fats and Fatty Acids, John Wiley, 



N. Y., 1958. 

 Hanahan, D. J. , Lipide Chemistry , John Wiley, N. Y. , 1960. 

 Hilditch, T. P. , The Chemical Constitution of Natural Fats 3rd ed. , John Wiley, N. Y. , 



1956. 

 Holman, R. T. , Lundberg, W. O. , and Malkin T. Progress in the Chemistry of Fats 



and Other Lipids . Pergamon Press, N. Y. , Vol. 1 (1954)-VoL 7 1960. 

 Kreger, D. R., "Wax" in Ruhland 10 249, 

 Lovern, J. A. , The Chemistry of the Lipids o| Biochemical Significance , 2nd ed, , John 



Wiley, N, Y. (1957). 

 Mader, H, , "Cutin" in Ruhland 10 270. 

 Mader, H. , "Kork" in Ruhland 10 282. 



Steiner, M. editor, The Metabolism of Fats and Related Compounds , Ruhland, 2- 

 Warth, A. H. , The Chemistry and Technology of Waxes , 2nd ed. , Reinhold, N. Y. , 1956. 



BIBLIOGRAPHY 



1. Zill, L. P. and Harmon, E. A., Biochim. Biophys. Acta 57 573 (1962). 



2. Downing, D. T. , Revs. Pure Appl. Chera. U 196 (1961). 



3. Bohlmann, F. and Mannhardt, H. J., Fortscher. Chem. Org. Naturstoffe , 14 1 (1957). 



4. Meade, E. M. , Prog. Chem. Fats Other Lipids 4 45 (1957). 



5. Gmjstone, F. D. , Prog. Org. Chem. _4 1 (1958). 



6. Jones, E. R. H. Proc. Chem. Soc. 1960 199. 



7. Kates, M. , Biochim. Biophys. Acta 31 315 (1960). 



8. Benson, A. A. and Strickland, E. H. , Biochim. Biophys. Acta 41 328 (1960). 



9. Woolley, D. W. , J. Biol. Chem. 147 581 (1943). 



10. Wagenknecht, A. C. , Lewin, L. M. and Carter, H. E. , J. Biol. Chem. 234 2265 (1959). 

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11. Carter, H. E. , Celmer, W. D , Lands, W. E. , Mueller, K. L. and Tomizawa, H. H. , J. Biol. Chem. 206 613 (1954). 



12. Carter, H. E. , Celmer, W. D. , Galanos, D. S. , Gigg, R. H. , Lands, W. E. M. , Law, J. H. , Mueller, K. L. , Nakayama, 



T. , Tomizawa, H. H. , and Weber, E. , J. Am. Oil Chemists Soc. 35 335 (1958). 



