[6o 



FINE-STRUCTURE OF PROTOPLASM 



II 



in a plane. This yields a dense film. When several layers of the kind 

 are superposed, a close-packed crystal lattice results (Fig. 84d, p. 126); 

 in this case every macromolecule is fixed by 1 2 junctions. This suggests 

 that the junctions are induced wherever the globules touch. Although 

 this seems true for crystallizing proteins, it would be difficult to under- 



O 



Fig. 104. Aggregation of globular macromolecules (dots = spots of junctions), a) Two 

 spots of junctions produce beaded chains; h) three spots of junctions produce porous 

 layers; c) four spots of junctions produce tetrahedral groups; d) twelve spots of junctions 



produce a close-packed crystal lattice. 



stand the formation of beaded chains and loose meshworks without 

 assuming a restricted possible number of junctions per aggregating 

 particle. In the case of globules aggregating to beaded chains, the 

 macromolecules must be endowed with a pronounced polarity. 



Summary. The proteins are to be considered as the structural ele- 

 ments of the cytoplasm. Their macromolecules are interlinked to form 

 a framework, whose junctions can be disrupted by various quite 

 different agents. A rise in temperature attacks in the first place the 

 homopolar cohesive bonds or lipidic bonds. Dependent on their state 

 of hydration, adsorbed salts affect the heteropolar cohesive bonds or 



