カワムラ　クニオ   KAWAMURA Kunio   川村　邦男    所属   広島修道大学  人間環境学部    職種   教授
言語種別	英語
発行・発表の年月	2004/06
形態種別	学術論文
査読	査読有り
標題	Behavior ofRNA under hydrothermal conditions and the origins of life
執筆形態	単著
掲載誌名	Int. J. Astrobiology
掲載区分	国外
巻・号・頁	3(4),pp.301-309
概要	The RNA world hypothesis and the hydrothermal origin of life hypothesis are contradictory to each other. Although it is considered that RNA molecules are too labile to maintain life-like systems at high temperatures, the stability and the chemical evolution of RNA have not been sufficiently analysed from the viewpoint of hydrothermal reactions. First, the stability of RNA molecules should be evaluated from the comparison of the rate of formation and the rate of degradation of RNA in open systems. Our prebiotic reaction models of phosphodiester bond formation suggest that at high temperatures the accumulation of RNA may be possible. Second, since enzymes presently mediate most biological reactions, evaluation of the accumulation of RNA should be based on the comparison between the enzymatic and non-enzymatic reaction rates. There is a large difference between the present enzymatic reaction rates at 25–90 °C and the non-enzymatic reaction rates at high temperatures of 200–300 °C.