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study should include the investigation of catalysis by mineral sur- 

 faces and metal ions, since little has been done to study the complex 

 interaction between organic and inorganic species on the putative 

 primitive Earth. 



Apart from the fashionable areas of amino acids and bases, the 

 synthesis of other biomonomers should be pursued. For example, is 

 the "formose" reaction the correct answer to the prebiotic formation 

 of the more important sugar compounds? Ribose is formed in low 

 yield by the base-catalyzed condensation of formaldehyde. A compli- 

 cated mixture of C 4 , C 5 , C 6 , and C 7 branched and linear sugars are 

 made in this reaction. Either ribose was formed under a more unique 

 set of reaction conditions or else there was a mechanism for the 

 selection of ribose from this complex mixture. In addition, we still 

 do not have prebiotic syntheses for long chain unbranched fatty 

 acids, alcohols, aldehydes, or isoprenes with relatively high yields. 



In the near future we can anticipate more work on membranes, 

 and two specific questions need to be resolved. How and when did 

 specific transport systems for solutes through lipid bilayers arise? 

 Can a plausible protocell be built from amphipathic lipids, proteins, 

 and (pre)nucleic acids? We anticipate a large input into prebiotic 

 chemistry from the experimental study of lipid bilayers, and research 

 in this area should be encouraged. 



An important adjunct to the question of the formation of bio- 

 monomers is the origin of optical asymmetry. For example, was the 

 selection of L-amino acids as the constituents of proteins a matter of 

 chance, or was it the result of some asymmetric process on the pre- 

 prebiotic Earth? Further work in these areas is warranted. 



In the last few years an abiotic synthesis of glycine has been 

 suggested as occurring in a spreading rift zone, specifically in the 

 Red Sea. This suggests that the submarine hydrothermal systems 

 should be studied as a possible model system for prebiotic chemistry. 



Environments on the Earth are subject to all kinds of fluctua- 

 tions: diurnal, seasonal, and tidal. For example, in some experiments 

 environmental fluctuations of temperature and moisture content 

 have been successfully used to produce peptides from amino acids. 

 Overall, how important were fluctuations for organic chemical evolu- 

 tion? Were they necessary? These are but two questions we can ask 

 relative to this potentially important regime. 



