Monoamino acids 

 reaction neutral 



Dipeptids 



Glycocoll 



Glycyl-glycin 



Alanin Alanyl-alanin 



Two possible dipeptids between glycocoll and alanin 



Glycyl-alanin 



Alanyl-glycirx 



Leucin 



Six possible tripeptids 

 between glycocoll, alanin. 

 and leucin 



Alanyl- glycyl-leucin 



L e ucyl- glycy 1- alanin 



Tyro sin 



Tryptophan 



Histidin 



Cy stein 



Straight chain polypeptid (heptapeptid) 

 Glycyl-alanyl-leucyl-tyrosyl-tryptophyl-histidyl-cystein 



PLATE I. SCHEMATIC REPRESENTATION OF THE AMINO ACIDS. 



The neutral amino acids each contain a basic arriino group (blue) and ail acid 

 carboxyl group (red), which neutralize each other. These amino acids can link 

 themselves to one another in straight chains, in any combination and permutation, 

 the amino group uniting with the carboxyl group. 



