[U-11] CO環境の生命惑星化学

[U11-P11] 蛇紋岩化環境におけるアミノ酸の合成と安定性に対する鉱物触媒反応の影響

*李 亜梅¹、黒川 宏之^1,2、関根 康人¹、癸生川 陽子^4,5、北台 紀夫³、Naizhong Zhang⁵、Xiaofeng Zang⁵、上野 雄一郎^5,1、Gen Fujimori⁴、龍平 中村¹、藤島 皓介¹、Junko Isa^6,1 (1.東京工業大学地球生命研究所、2.東京大学、3.日本海洋研究開発機構、4.横浜国立大学、5.東京工業大学地球惑星科学系、6.千葉惑星探査研究センター)

キーワード：生命起源、アミノ酸、鉱物における触媒化学、炭素質コンドライト、小惑星Ryugu

Origins of life on early Earth and other habitable environments remains to be solved. The exploration on this question provides critical guide for deep-Earth and extraterrestrial life exploration and evaluating the habitability of extraterrestrial bodies. One of the central questions is the origin, evolution and distribution of life’s building block molecules in the context of Solar System evolution. Water/rock interaction systems distribute widely on Earth, early Mars, and icy satellites (e.g., Enceladus). Such systems are closely related to these bodies’ habitability because they can possibly provide water, energy as well as organics in one place that are considered to be required for life emergence. Besides these inner system bodies, at the early stage of Solar System evolution, the icy planetesimals formed beyond the water snow line also featured water/rock interactions. These water/rock interactions could have created and/or decomposed organic compounds. Based on the observations on carbonaceous chondrites and recent return samples from C-type asteroid Ryugu, life’s critical building block, namely amino acids, could have been widely distributed in our Solar System and thus contributed to the life emergence on the Early Earth and possibly elsewhere. The amino acid abundance records suggest the important role of parent body water/rock interactions on shaping their distributions.
Here in my abstract, I will introduce how water/rock interactions create an environment with thermodynamic disequilibria. Minerals can mediate the electron transfer to facilitate the energy conversion in the mode of geo-electrochemistry for either creating or decomposing life’s building block molecules. Such decomposition can also generate hydrogen cyanide that is considered to be hub molecule for protometabolism. The stabilization/decomposition processes could provide an important selection mechanism for directing the origin of life.