The first cell membranes.
Organic compounds are synthesized in the interstellar medium and can be delivered to planetary surfaces such as the early Earth, where they mix with endogenous species. Some of these compounds are amphiphilic, having polar and nonpolar groups on the same molecule. Amphiphilic compounds spontaneously self-assemble into more complex structures such as bimolecular layers, which in turn form closed membranous vesicles. The first forms of cellular life required self-assembled membranes that were likely to have been produced from amphiphilic compounds on the prebiotic Earth. Laboratory simulations show that such vesicles readily encapsulate functional macromolecules, including nucleic acids and polymerases. The goal of future investigations will be to fabricate artificial cells as models of the origin of life.
Deamer
David
D
Department of Chemistry and Biochemistry, University of California at Santa Cruz, Santa Cruz, California 95064, USA. deamer@hydrogn.ucsc.edu
Dworkin
Jason P
JP
Sandford
Scott A
SA
Bernstein
Max P
MP
Allamandola
Louis J
LJ
D005075:Biological Evolution; D002462:Cell Membrane; D002477:Cells; D018534:Earth, Planet; D018559:Exobiology; D005118:Extraterrestrial Environment; D008954:Models, Biological; D000069497:Origin of Life