100 



POLAR HEAD 



NONPOLAR 

 TAILS 



WATER 



WATER 



Figure V-6.— The membranes of most living cells are made up of (a) phospho- 

 lipids. They spontaneously form a lipid bilayer (b) in water as illustrated above. 



research directions. For instance, it is likely that the charged sur- 

 faces, like those of clays, have catalytic properties, and this possibil- 

 ity should certainly be investigated. 



The hydrophobic moiety also holds considerable interest. All 

 contemporary light energy transducing systems depend on a non- 

 polar membrane phase to embed specialized pigments and enzymes, 



