200 LIFE: ITS NATURE AND ORIGIN 



carriers and prosthetic groups for still other catalysts. Changes 

 in aggregation and particle size will also greatly influence kinetic 

 activity, diffusibility, passage through septa, adsorbability, and 

 the nature and extent of the outwardly directed electronic mosaic. 

 With the biologically important colloid proteins, as indeed with 

 most other substances, we must, at a certain stage of organization, 

 envisage the possibility of particulate unions and dissociations 

 which are not comprehensible in terms of simple stoichiometry, 

 even though they are due to residues of the same subatomic 

 potencies which are responsible for chemical attraction. There 

 comes a zone in the successive levels of increasing complexity of 

 material structure, where the externally directed electronic mo- 

 saics of the particulate units may be somewhat variable and af- 

 fected by adsorbed "impurities," and yet the attraction (or 

 repulsion) of the units may be biologically important (e.g., con- 

 sider mitosis and "crossing over"), although not as powerful or as 

 precise as with true chemical combinations between smaller and 

 less organized particulate units. 



As to elation, we need only recall the masterly work of Richard 

 Willstatter, 38 who concentrated enzymes several thousand fold by 

 adsorbing them on suitable adsorbents, filtering off the exhausted 

 fluid, and then stripping off or eluting the adsorbed enzyme from 

 the adsorbent by slight changes in the pH or the chemical nature 

 of the dispersion medium. Besides being important in many 

 analytical procedures (e.g., chromatography), this process of selec- 

 tive adsorption and differential elution has extensive industrial 

 applications; for example, the important drug penicillin was 

 concentrated from highly dilute dispersions by adsorption on 

 activated carbon, and was eluted from the carbon by a suitable 

 solvent. 39 



An eluate may, in turn, serve as an elutor of other substances 

 from the adsorbed state; or it may act as a prosthetic group, a 

 carrier, a complete enzyme, or as an inhibitor of enzymes. 



It must also be considered that the formation and release, at 

 catalyst surfaces, of substances of low diffusive mobility may 

 establish local concentrations of these substances far higher than 

 their average distribution as shown by an overall chemical deter- 

 mination. In fact, a number of geneticists have applied this 

 notion of accumulation to explain the "position effect." 40 In- 

 creased length of the diffusion path tends to limit the distribution 

 of the output of a catalyst surface, and this, in turn, may affect 



