86 THE FATS AND LIPASES [ch. vi 



and a fatty acid, e.g. in\^ristic acid : 



H3C— CH, • CHa • CH.j ■ CH. • CH. • CH. ■ CH, • CH, • CH, • CH, • CH, • CH, • COOH 

 it is seen that three main changes are concerned in the synthesis of 

 such a fatty acid from sugar, i.e. reduction of the hydroxyl groups of the 

 sugar, conversion of the aldehyde group into an acid group, and finally 

 the condensation or linking together of chains of carbon atoms. " An 

 interesting fact in connexion with this point is that all naturally occur- 

 ring fatty acids have a straight, and not a branched, carbon chain. It 

 has been suggested (Smedley, etc., 11-13) that acetaldehyde and a 

 ketonic acid, pyruvic acid, may be formed from sugar. By condensation 

 of aldehyde and acid, another aldehyde is formed with two more carbon 

 atoms. By repetition of the process, with final reduction, fatty acids 

 with straight chains are produced. 



REFERENCES 



Books 



1. Abderhalden, E. Biochemisches Handlexikon, iii. Berlin, 1911. 



2. Leathes, J. B. The Fats. London, 1910. 



3. Allen's Commercial Organic Analysis. Vol. 2. London, 1910. 



Papers 



4. Armstrong, H. E. Studie.s on Enzyme Action. Lipa.se. Proc. R. Soc:, 

 190.5, B Vol. 76, pp. 606-608. 



5. Armstrong, H. E., and Ormerod, E. Studies on Enzyme Action. 

 Lipase. II. Proc. R. Sac, 1906, B Vol. 78, pp. 376-385. 



6. Armstrong, H. E., and Gosney, H. W. Studies on Enzyme Action. 

 Lipase. III. J'roc. R. Soc, 1913, B Vol. 86, pp. 586-600. 



7. Armstrong, H. E., and Gosney, H. W. Studies on Enzyme Action. 

 Lipase. IV. The Correlation of Synthetic and Hydrolytic Activity. Proc. R. Soc, 

 1915, B Vol. 88, pp. 176-189. 



8. Miller, E. C. A Physiological Study of the (iermination of Helianthus 

 annuus. Ann. Bot., 1910, Vol. 24, pp. 693-726. Ibid. 1912, Vol. 26, pp. 889-901. 



9. Reynolds Green, J. On the Germination of the Seed of the Castor-oil 

 Plant {Ricinvs rommuniii). Proc R. Soc, 1890, Vol. 48, pj). 370-392. 



10. Reynolds Green, J., and Jackson, J. Further Observations on the 

 Germination of the Seeds of the Castor-oil Plant (RicimiH coinmunis). Proc. R. Soc, 

 1906, B Vol. 77, ])p. 69-85. 



1 1 . Smedley, I. The Biochemical Synthesis of Fatty Acids from Carbohydrate. 

 J. Pliysiol., 1912, Vol. 45, pp. xxv-xxvii. 



12. Smedley, I., and Lubrzynska, E. The Biochemical Synthesis of the 

 Fatty Acids. Jh'ochem. J., 1913, Vol. 7, pp. 364-374. 



13. Lubrzynska, E., and Smedley, I. The Condensation of Aromatic 

 Aldehydes with I'yruvic Acid. Biochem. ./., 1913, Vol. 7, pp. 375-379. 



