Sedimentary Minerals, Organic Chemical Transformations, and the Origin of Life

我们对43.5亿年前地球地质环境的了解已经发展到地质学可以与有机化学相结合的地步，不需要人为控制就可以建立第一个遗传分子如何出现在地球上的模型，也可能出现在火星等岩石行星上。这种“不干涉”的化学反应可以在这些环境中存在的岩石的背景下进一步简化。这种结合现在使我们能够推进与人类提出的最古老的问题之一有关的科学知识：我们从哪里来？此外，该项目将开发的益生元化学的简单性使学生，即使是高中生也可以使用。除了推动科学发展外，该项目还将向学生提供工具包，让他们参与到与这个“大问题”相关的地球化学领域中。这种地质化学组合支持生命起源的“RNA第一假说”，即达尔文进化论是基于核糖核酸的非生物形成而出现的，核糖核酸是其第一个信息分子。在这里，地质环境包括间歇性干燥、受约束的含水层，这些含水层通过雨水接收由火山二氧化硫稳定的小碳水化合物、还原的含氮有机分子和其他物种，这些物种是由紫外线和大气中的放电产生的，而大气中的放电是由撞击体核心碎片中的铁还原的。 地质环境包括来自氧化还原中性地壳的围岩，包括硼酸盐蒸发岩矿物，以及年轻地球上的撞击和火山活动产生的玄武玻璃。 玄武岩玻璃含有脱水磷酸盐，可以作为催化剂组装RNA。 在这个单一的环境中，小的有机物可以通过一个过程产生100-200个核苷酸长的寡聚RNA，该过程起始于硼酸盐控制的稳定碳水化合物的成熟，通过玻璃递送的多磷酸的磷酸化，核糖环磷酸与核碱基反应以产生核苷酸，硼酸盐调节的磷酸化产生核苷三磷酸。本项目将通过撞击玻璃完成三磷酸盐形成的RNA产物的结构分析，将碳水化合物加工与下游核苷合成相结合，探索该环境产生纯手性产物的可能性，该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准。

Our understanding of geological environments on Earth 4.35 billion years ago has advanced to the point where geology can be combined with organic chemistry that does not need careful human control to build models for how the first genetic molecules might have emerged on Earth, and possibly on other rocky planets like Mars. This "hands off" chemistry can be further simplified in the context of rocks present in those environments. This combination now allows us to advance scientific knowledge relevant to one of the oldest questions posed by humankind: Where did we come from? Further, the simplicity of the prebiotic chemistry that this project will develop makes it accessible to students, even those in high school. In addition to advancing the science, this project will deliver kits to those students that will let them participate in the current excitement in geochemistry relevant to this "big question".This geology-chemistry combination supports the "RNA first hypothesis" for the origin of life, which holds that Darwinian evolution emerged based on the abiological formation of ribonucleic acid that served as its first informational molecule. Here, the geological environment comprises intermittently dry, constrained aquifers that receive by rain small carbohydrates stabilized by volcanic sulfur dioxide, reduced nitrogen-containing organic molecules, and other species that were created by UV and electrical discharge in atmospheres that had been reduced by iron fragmented from the cores of impacting bodies. The geological environment includes surrounding rocks from a redox neutral crust, including borate evaporite minerals, as well as basaltic glass generated by the impacts and volcanism on the young Earth. The basaltic glass contains dehydrated phosphates which can serve as a catalyst to assemble RNA. In this single environment, small organics can yield oligomeric RNA 100-200 nucleotides long by a process that initiates with borate-controlled maturation of stabilized carbohydrates, phosphorylation by glass-delivered polyphosphates, reaction of ribose cyclic phosphates with nucleobases to give nucleotides, with borate-moderated phosphorylation yielding nucleoside triphosphates. This project will complete structure analysis of RNA products formed from triphosphates by impact glass, integrate carbohydrate processing with downstream nucleoside synthesis, explore the possibility of this environment producing homochiral products, and develop the sedimentary and igneous geology of relevant minerals for students to work with.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.