Abstract EANA2025-166

The origin of life requires the presence of various organic compounds necessary for expressing biological functions. In modern organisms, these include proteins that are involved in metabolism, polynucleotides that are involved in genetics, and lipids that constitute biological membranes. There has been much debate about which component was the most important component was for the origin of life. The recent discovery of ribozymes, which exhibit catalytic functions, has led to the prevailing view that RNA is the most important. However, some argue that proteins or polyamino acids, formed by the condensation of amino acids, which are more important because amino acids are found throughout the universe, and easily condense in the prebiotic environments. Conversely, some propose that life originated from complex organic mixtures consisting of various substances with inconsistent chemical structures. While it is difficult to determine when life first emerged in the process of chemical evolution, but it is important to note that these components were not isolated, but rather organically connected and exhibited new functions. Regardless of whether it was an RNA world, a protein world, or a complex organic world, these components were not isolated but rather organically connected and exhibited new functions. In this paper, we consider amino acids as starting materials. Amino acids are are abundant in various cosmic samples, such as carbonaceous chondrites, moon fines, cometary dust, and asteroid samples, as well as in simple experimental systems, such as Miller's experiment. We provide an overview of their condensation reactions and the functions and roles of their condensation products.

Many reports have described amino acid condensation reactions in the primordial Earth and cosmic environments. Most of these reports involve synthesizing molecules up to 10-mers. However, polyamino acids synthesized in a molten state have molecular weights ranging from several thousand to 10,000, as determined by gel permeation chromatography. The polyamino acids synthesized in the molten state include thermal proteinoids synthesized from monammonium malate and polyamino acids synthesized in urea. These reactions demonstrate that copolymers of multiple amino acids, rather than just a single amino acid, are synthesized. Furthermore, some form spherical structures on the micrometer scale that are nearly the same size as microorganisms. These spherical structures, known as proteinoid microspheres, can incorporate organic molecules. Some of these microspheres can also incorporate nucleic acids, though self-replication has not been confirmed. Nevertheless, they exhibit functions similar to viruses in delivering nucleic acids to other cells. Based on these findings, it is possible that polyamino acids synthesized in the molten state played an important role in chemical evolution.