SUGGESTIONS TO TEACHERS OF BIOCHEMISTRY 



I. A proposed chemical Classification of lipins, with a note on 

 the intimate relation between cholesterols and bile salts 



JACOB ROSENBLOOM and WILLIAM J. GIES 



{Laboratory of Biological Chemistry of Columbia University, at the College of 

 Physicians and Surgeons, New York.) 



I. A GENERAL CHEMICAL CLASSIFICATION OF LIPINS 



The teacher of biological chemistry who aims to speak definitely 

 and with precision regarding the fats, and the substances resembling 

 them ("Hpoids"), finds himself in a quandry. He may adopt one 

 of the several current classifications. If he does, he will use terms 

 which, in many cases, convey very little chemical meaning to his 

 pupils at the outset of their work. He may modify an established 

 Classification to render it more appropriate to his immediate 

 needs. Such a concession to pedagogic expediency is apt to cause 

 confusion when the Classification is found to differ from a conven- 

 tional grouping in the text books. He may propose and teach a 

 Classification of his own. The new Classification may be less useful 

 than its predecessors, especially in the estimation of his colleagues. 



With possibly such a fate as this awaiting it, we venture to pro- 

 pose the accompanying chemical Classification of fats and the many 

 substances related to or resembling them, which coUectively can 

 be very appropriately and conveniently called lipins (pp. 52-53). 



Our Classification of the lipins has been in the process of gradual 

 development in our teaching and research here for several years, 

 and has been serving a useful purpose, meanwhile, in both Instruc- 

 tion and investigation. It helps investigators, teachers, and pupils 

 to get and to keep their bearings in chemical studies of this great 

 group of substances. Further additions to our knowledge of the 

 lipins will naturally extend the ränge and accuracy of this Classifi- 

 cation, an outcome to which we are giving continuous attention. 



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