ORIGINS - Organic molecular generation of protocells on iron minerals

生命是如何在地球上起源的是一个尚未解决的重大科学问题。虽然没有岩石在地球历史的早期幸存下来，但我们可以从今天微生物中仍然存在的生物“化石”证据的碎片中获得线索，考虑早期地球环境可能是什么样的，并通过观察现代地球上的类似环境。总之，这些证据与生命起源于温暖到高温（< 150摄氏度）的碱性热液喷口（“温泉”）一致，在那里，富含铁的矿物质帮助热液喷口中的氢气和海洋或地表水中的二氧化碳发生反应，形成生命的有机“基石”。然而，有一个问题是，在相关条件下试图模拟这种化学反应的实验只形成了长度不超过3个碳原子的非常短的有机分子。它们太短了，无法构建更大的有机生命“积木”；最重要的是细胞膜，它将细胞（生命的基本单位）与外界的水分离开来，以控制化学梯度和后来的内部生物化学进化。在ORIGINS中，我们将以纽卡斯尔大学一项试点研究的令人兴奋的新实验结果为基础，在该研究中，我们在模拟碱性热液与水在< 100℃下混合的条件下，在铁矿物上形成了长链有机分子（包括细胞膜的构建块）。我们将确定不同的铁矿物和水化学物质如何形成早期生命的关键有机构建块。然后，我们的目标是展示这些有机构建块如何在适当的条件下，剥离矿物质并自组装成“原始细胞”；与现代微生物细胞非常相似的膜结合有机球；是通往人生的关键垫脚石。最后，我们将采取第一步来测试这些原始细胞是否可以使用嵌入其中的金属矿物簇来产生进一步的有机分子，生长和复制。ORIGINS将对地球和其他地方产生影响。研究将与英格兰东北部的一个推广项目联系起来，利用互动式讲习班激励学龄儿童继续学习以科学为基础的课程。ORIGINS还将有助于在太阳系其他地方寻找生命。冰冷的卫星，如木星的卫星木卫二和土星的卫星土卫二，被认为在它们被冰覆盖的深海底部有类似的碱性热液喷口，热液喷口的样本被热液羽状物带到卫星表面或被驱逐到太空中。我们将连接到最近发射的欧洲航天局JUICE（木星冰卫星探测器）任务，该任务最近开始了为期八年的木星冰卫星探索之旅。在ORIGINS实验中获得的有机分子和原始细胞样本将被用于测试JUICE航天器上相同仪器的能力，以在其到达之前检测卫星表面的有机分子。

How life originated on our planet is one of the great unsolved scientific questions. While no rocks survive from this early in Earth's history, clues can be gained from scraps of evidence from biological 'fossils' still present in microorganisms today, a consideration of what early Earth environments were probably like, and by looking at similar environments on the modern Earth. Together the evidence is consistent with an origin of life at warm to hot (< 150 deg C) alkaline hydrothermal vents ('hot springs'), where iron-rich minerals helped react hydrogen gas from the hydrothermal vents and carbon dioxide from the oceans or surface water into the organic 'building blocks' of life. One problem, however, is that experiments trying to mimic this chemistry under relevant conditions have only formed very short organic molecules of 3 carbon atoms in length or less. These are too short to build the larger organic 'building blocks' of life; most importantly cell membranes essential for separating the cell (the basic unit of life) from outside water to allow the control of chemical gradients and later evolution of internal biochemistry.In ORIGINS we will build on exciting new experimental results from a pilot study at Newcastle University where we have formed long chains of organic molecules (including the building blocks of cell membranes) on iron-minerals under conditions mimicking the mixing of alkaline hydrothermal vent fluid with water at < 100 deg C. We will determine how different iron-minerals and water chemistries can form the key organic building blocks of early life. We will then aim to show how these organic building blocks can, given the right conditions, lift off the minerals and self-assemble into 'protocells'; membrane-bounded organic spheres with a strong resemblance to modern microbial cells; a key stepping-stone to life. Finally, we will take the first steps to test if these protocells can use metal-mineral clusters embedded within them to generate further organic molecules, grow, and replicate.ORIGINS will have impact on both Earth and beyond. Research will be linked to an outreach program in the NE of England, using interactive workshops to inspire school age children to continue with science-based subjects. ORIGINS will also aid the search for life elsewhere in our solar system. Icy moons such as Jupiter's moon Europa and Saturn's moon Enceladus are thought to have similar alkaline hydrothermal vents at the bottom of their deep ice-covered oceans, and samples of them brought up by hydrothermal plumes to the moons' surfaces or expelled into space. We will link into the recently launched European Space Agency JUICE (Jupiter Icy Moons Explorer) mission, recently started on its eight year journey to explore Jupiter's icy moons. Samples of the organic molecules and protocells made in ORIGINS experiments will be used to test the ability of identical instruments to those on the JUICE spacecraft to detect organic molecules on the moons' surfaces prior to its arrival.