288 



CELL HEREDITY 



FIGURE 10.8. Models of the a- and /3-polypeptide chains of hemoglobin (from Perutz 

 etal., ]960, Nature, 185:416). 



Top. One each of the a- and of the /3-chains, showing the path of the a-helix traced 

 onto the model as a black solid and dotted line. The heme groups are at the backs of the 

 chains and therefore not visible. 



