BIOLOGICAL ORDER 



The Molecular Basis 

 of Enzymatic Specificity 



Enzymes are proteins. Proteins are composed of twenty species 

 of amino acids (Figure 6). If, in two protein molecules, these twenty 

 species are organized into one and the same sequence, the two 



Figure 6. The Molecule of Ribonuclease (from C. B. Anfinsen, 

 The Molecular Basis of Evohitio?i). 



molecules are necessarily identical. The polypeptide chain of a pro- 

 tein is folded, but it will be admitted that folding depends on the 

 sequence of amino acids and that two identical polypeptide chains 



[22] 



