Prebiotic Fatty Acid Vesicles through Photochemical Dissipative Structuring

TL;DR

This paper proposes a photochemical process that could have led to the formation of fatty acid vesicles in early Earth's oceans, potentially serving as precursors to protocells by harnessing solar UV radiation.

Contribution

It introduces a novel mechanism of photochemical dissipative structuring of fatty acids, explaining the formation of stable vesicles under Archean conditions and their role in early life evolution.

Findings

Vesicles formed from conjugated linolenic and parinaric acids are stable at high temperatures.

These vesicles are resistant to divalent cation salt flocculation.

They are permeable to ions and small charged molecules, but impermeable to short DNA and RNA.

Abstract

We describe the photochemical dissipative structuring of fatty acids from CO and CO2 saturated water under the solar UVC and UVA photon potential prevalent at Earth's surface during the Archean. Their association into vesicles and their subsequent association with other fundamental molecules of life such as RNA, DNA and carotenoids to form the first protocells is also suggested to occur through photochemical dissipative structuring. In particular, it is postulated that the first vesicles were formed from conjugated linolenic (C18:3n-3) and parinaric (C18:4n-3) acids which would form vesicles stable at the high temperatures (~85 {\deg}C) and the somewhat acidic pH values (6.0-6.5) of the Archean ocean surface, resistant to divalent cation salt flocculation, permeable to ions and small charged molecules, but impermeable to short DNA and RNA, and, most importantly, highly dissipative in the prevailing UVC+UVA regions.