CHED 756 |
| Many current theories for the origin of life rely upon the validity of the hypothesis that RNA came before proteins or DNA (the “RNA world” hypothesis). The capacity of RNA to both store information and perform catalysis certainly makes this polymer an attractive candidate as this first polymer of life. However, a major difficulty for the RNA world hypothesis is the problem of how the first RNA polymers formed without the aid of coded proteins. The lack of a simple and plausible prebiotic scenario for the spontaneous formation of RNA from smaller building blocks (e.g. bases, sugars and phosphate) has caused many researchers to conclude that RNA was preceded by another informational polymer that was eventually replaced by RNA over the course of evolution. We have hypothesized that the first informational polymers of life contained chemical building blocks that were similar in functionality to the contemporary building blocks of RNA, but distinct in that they were capable of participating in the formation of multimolecular assemblies and low energy covalent bonds that facilitated the formation of RNA-like polymers. We also hypothesize that short non-coded peptides, formed by the spontaneous coupling of amino acids in drying-heating reactions, assembled into surfaces and vesicles that facilitated the emergence of life by acting as selective catalysts, including catalysts for the synthesis of molecules required for the emergence of RNA. Our laboratories are currently working in a highly collaborative mode to test and refine these hypotheses. We will discuss experimental results which demonstrate how multimolecular assemblies of small molecules and peptides may have acted to bring about the earliest informational polymers of life. |
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Chemical Evolution from Origins of Life to Modern Society
1:30 PM-4:55 PM, Monday, April 7, 2008 Hilton New Orleans Riverside -- Jasperwood, Oral
Division of Chemical Education |