Protocell

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模板:Distinguish

模板:Evolutionary biology

A protocell (or protobiont) is a self-organized, endogenously ordered, spherical collection of lipids proposed as a stepping-stone toward the origin of life.[1][2] A central question in evolution is how simple protocells first arose and how they could differ in reproductive output, thus enabling the accumulation of novel biological emergences over time, i.e. biological evolution. Although a functional protocell has not yet been achieved in a laboratory setting, the goal to understand the process appears well within reach.[3][4][5][6]

原生细胞(或原生生物体)是一个自我组织的、内生有序的球形脂质集合体,被认为是通往生命起源的垫脚石。进化中的一个中心问题是,原始细胞是如何产生的,以及它们如何在生殖输出上有所不同,从而使得新的生物学现象随着时间的推移而积累起来。生物进化。虽然在实验室环境中还没有实现功能性的原始细胞,但是理解这一过程的目标似乎是可以实现的。

[终译]原始细胞(或原始生物)是一个自组织的、内在有序的球形脂质集合体,被认为是通往生命起源的垫脚石。进化中的一个中心问题是,简单的原始细胞是如何产生的,以及它们如何在繁殖输出上有所不同,从而使得新的生物学现象随着时间的推移而积累起来,即生物进化。虽然在实验室环境中还没有实现功能性的原始细胞,但是理解这一过程的目标似乎是可以实现的。

Overview ==概述==

Compartmentalization was模板:When important in the origins of life.[citation needed] Membranes form enclosed compartments that are separate from the external environment, thus providing the cell with functionally specialized aqueous spaces. As the lipid bilayer of membranes is impermeable to most hydrophilic molecules (dissolved by water), cells have membrane transport-systems that achieve the import of nutritive molecules as well as the export of waste.[7]模板:Qn It is very challenging to construct protocells from molecular assemblies. An important step in this challenge is the achievement of vesicle dynamics that are relevant to cellular functions, such as membrane trafficking and self-reproduction, using amphiphilic molecules. On the primitive Earth, numerous chemical reactions of organic compounds produced the ingredients of life.[citation needed] Of these substances, amphiphilic molecules might be the first player in the evolution from molecular assembly to cellular life.[8][9] A step from vesicle toward protocell might be to develop self-reproducing vesicles coupled with the metabolic system.[10]

在生命起源中,防火分区是很重要的。膜形成与外部环境分离的封闭隔间,从而为细胞提供了功能特殊的水空间。由于膜上的脂质双分子层对大多数亲水分子(被水溶解)是不透水的,因此细胞具有膜转运系统,既输入营养分子,又输出废物。由分子组装来构建原始细胞是一项非常具有挑战性的工作。这一挑战的一个重要步骤是利用两亲分子实现与细胞功能相关的囊泡动力学,如膜贩运和自我复制。在原始的地球上,许多有机化合物的化学反应产生了生命的成分。在这些物质中,两亲分子可能是从分子组装进化到细胞生命的第一个参与者。从小泡到原细胞的一个步骤可能是发展自我繁殖小泡与代谢系统相结合。

[终译]在生命起源中,区室化是很重要的。膜形成与外部环境分离的封闭隔室,从而为细胞提供了功能特殊的含水空间。由于膜上的脂质双分子层对大多数亲水分子(被水溶解)是不可渗透的,因此细胞具有膜转运系统,既输入营养分子,又输出废物。由分子组装来构建原始细胞是一项非常有挑战的工作。这一挑战的一个重要步骤是利用两亲分子实现与细胞功能相关的囊泡动力学,如跨膜运输和自复制。在原始地球上,许多有机化合物的化学反应产生了生命成分。在这些物质中,两亲分子可能是从分子组装进化到细胞生命的第一个参与者。从囊泡到原始细胞的一个步骤可能是发展可自复制的囊泡与代谢系统相结合。

Another approach to the notion of a protocell concerns the term "chemoton" (short for 'chemical automaton') which refers to an abstract model for the fundamental unit of life introduced by Hungarian theoretical biologist Tibor Gánti.[11] It is the oldest known computational abstract of a protocell. Gánti conceived the basic idea in 1952 and formulated the concept in 1971 in his book The Principles of Life (originally written in Hungarian, and translated to English only in 2003). He surmised the chemoton as the original ancestor of all organisms, or the last universal common ancestor.[12]

原细胞概念的另一种方法涉及术语“ chemoton”(‘化学自动机’的缩写) ,它指的是匈牙利理论生物学家 Tibor Gánti 介绍的基本生命单位的抽象模型。这是已知最古老的原始细胞计算摘要。1952年,Gánti 构想了这个基本概念,并于1971年在他的《生活的原则》一书中阐述了这个概念(最初用匈牙利语写成,2003年才翻译成英语)。他推测化学吨是所有生物体的原始祖先,或是最后的共同祖先。

[终译]原始细胞概念的另一种途径涉及术语“chemoton”(‘化学自动机’的缩写) ,它指的是匈牙利理论生物学家 Tibor Gánti 引进的基本生命单位的抽象模型。这是已知最早的原始细胞计算抽象模型。1952年,Gánti 构想了这个基本概念,并于1971年在他的《生活的原则》一书中阐述了这个概念(最初用匈牙利语写成,2003年才翻译成英语)。他推测化学自动机是所有生物的原始祖先,或是最后的共同祖先。

The basic assumption of the chemoton model is that life should fundamentally and essentially have three properties: metabolism, self-replication, and a bilipid membrane.[13] The metabolic and replication functions together form an autocatalytic subsystem necessary for the basic functions of life, and a membrane encloses this subsystem to separate it from the surrounding environment. Therefore, any system having such properties may be regarded as alive, and it will be subjected to natural selection and contain a self-sustaining cellular information. Some consider this model a significant contribution to origin of life as it provides a philosophy of evolutionary units.[14]

化学吨模型的基本假设是,生命从根本上应该具有三种属性: 新陈代谢、自我复制和双生膜。新陈代谢和复制功能共同构成了生命基本功能所必需的自动催化子系统,而膜包裹这个子系统以将其与周围环境分离开来。因此,任何具有这些属性的系统都可以被视为是活的,它将受制于自然选择,并包含一个自我维持的细胞信息。有些人认为这个模型对生命起源做出了重大贡献,因为它提供了进化单位的哲学。

[终译]化学自动机模型的基本假设是,生命从根本上应该具有三种属性:代谢、自复制和双层脂膜。代谢和复制功能共同构成了生命基本功能所必需的自催化子系统,而膜包裹这个子系统以将其与周围环境分离开来。因此,任何具有这些属性的系统都可以被视为是活的,它将受制于自然选择,并包含一个自维持的细胞信息。有些人认为这个模型对生命起源做出了重大贡献,因为它提供了进化单位的哲学原理。

Selectivity for compartmentalization ==对区室化的选择性==

文件:Phospholipids aqueous solution structures.svg
The three main structures phospholipids form in solution; the liposome (a closed bilayer), the micelle and the bilayer. 磷脂在溶液中形成三种主要结构;脂质体(封闭的双层膜),微胶粒和双层膜。  

Self-assembled vesicles are essential components of primitive cells.[1] The second law of thermodynamics requires that the universe move in a direction in which disorder (or entropy) increases, yet life is distinguished by its great degree of organization. Therefore, a boundary is needed to separate life processes from non-living matter.[15] The cell membrane is the only cellular structure that is found in all of the cells of all of the organisms on Earth.[16]

= = 对防火分区的选择性 = = 自组装囊泡是原始细胞的重要组成部分。热力学第二定律理论要求宇宙朝着无序(或熵)增加的方向运动,然而生命以其巨大的组织程度而著称。因此,需要一个界限来区分生命过程和非生命物质。细胞膜是地球上所有生物体的所有细胞中唯一的细胞结构。

[终译]自组装囊泡是原始细胞的重要组成部分。热力学第二定律理论要求宇宙朝着无序性(或)增加的方向运动,然而生命以其巨大的组织自由度而著称。因此,需要一个界限来将生命过程从非生命物质中区分出来。细胞膜是地球上所有生物的细胞中唯一共有的细胞结构。

In an aqueous environment in which all known cells function, a non-aqueous barrier is required to surround a cell and separate it from its surroundings.[17] To be an entity, distinguished from the environment, requires a barrier to free diffusion. The necessity of thermodynamically isolating a subsystem is an irreducible condition of life.[17] Such isolation is ordinarily accomplished by membranes, amphiphilic bilayers of a thickness of around 10−8 meters.

在一个所有已知细胞都发挥作用的水环境中,需要一个非水屏障来包围细胞并将其与周围环境分开。作为一个实体,区别于环境,需要一个自由扩散的障碍。从热力学角度分离子系统的必要性是生命的不可约条件。这种隔离通常是通过膜完成的,这种两亲性双层膜的厚度约为10-8米。

[终译]在一个所有已知细胞都发挥功能的水环境中,需要一个非水屏障来包围细胞并将其与周围环境分开。区别于环境,作为一个实体需要一个自由扩散的障碍。从热力学角度分离子系统的必要性是生命的不可约条件。这种隔离通常是通过膜完成的,这种两亲性双层膜的厚度约为10-8米。

Researchers Irene A. Chen and Jack W. Szostak (Nobel Prize in Physiology or Medicine 2009) amongst others, demonstrated that simple physicochemical properties of elementary protocells can give rise to simpler conceptual analogues of essential cellular behaviors, including primitive forms of Darwinian competition and energy storage. Such cooperative interactions between the membrane and encapsulated contents could greatly simplify the transition from replicating molecules to true cells.[4] Competition for membrane molecules would favor stabilized membranes, suggesting a selective advantage for the evolution of cross-linked fatty acids and even the phospholipids of today.[4] This micro-encapsulation allowed for metabolism within the membrane, exchange of small molecules and prevention of passage of large substances across it.[18] The main advantages of encapsulation include increased solubility of the cargo and creating energy in the form of chemical gradient. Energy is thus often said to be stored by cells in the structures of molecules of substances such as carbohydrates (including sugars), lipids, and proteins, which release energy when chemically combined with oxygen during cellular respiration.[19][20]

研究人员 Irene a. Chen 和 Jack w. Szostak (诺贝尔生理学或医学奖2009年)等人证明,基本原始细胞的简单物理化学性质可以产生基本细胞行为的简单概念类似物,包括达尔文竞争和能量储存的原始形式。这种膜和包膜内容物之间的协同作用可以极大地简化从复制分子到真正细胞的过渡。对膜分子的竞争将有利于稳定化膜,这表明交联脂肪酸甚至今天的磷脂的进化具有选择性优势。这种微囊化可以促进膜内的新陈代谢,交换小分子,防止大型物质通过膜。包封的主要优点包括增加货物的溶解度和以化学梯度的形式产生能量。因此,能量通常被认为是由细胞以碳水化合物(包括糖)、脂类和蛋白质等物质的分子结构储存的,这些物质在唿吸作用期间与氧化合时释放能量。

[终译]研究人员 Irene a. Chen 和 Jack w. Szostak(诺贝尔生理学或医学奖2009年)等人证明,基本原始细胞的简单物理化学性质可以产生基本细胞行为的简单概念类似物,包括达尔文竞争和能量储存的原始形式。这种膜和包膜内容物之间的协同作用可以极大地简化从复制分子到真正细胞的过渡。对膜分子的竞争将有利于稳定膜,这表明交联脂肪酸甚至今天的磷脂的进化都具有选择性优势。这种微囊化可以促进膜内的新陈代谢,交换小分子,防止大型物质通过膜。包膜的主要优点包括增加物质的溶解度和以化学梯度的形式产生能量。因此,能量通常被认为是由细胞以碳水化合物(包括糖)、脂类和蛋白质等物质的分子结构储存的,这些物质在细胞呼吸期间与氧化合时释放能量。

Energy gradient ==能量梯度==

A March 2014 study by NASA's Jet Propulsion Laboratory demonstrated a unique way to study the origins of life: fuel cells.[21] Fuel cells are similar to biological cells in that electrons are also transferred to and from molecules. In both cases, this results in electricity and power. The study states that one important factor was that the Earth provides electrical energy at the seafloor. "This energy could have kick-started life and could have sustained life after it arose. Now, we have a way of testing different materials and environments that could have helped life arise not just on Earth, but possibly on Mars, Europa and other places in the Solar System."[21]

2014年3月,美国国家航空和宇宙航行局的喷气推进实验室科学研究所展示了一种研究生命起源的独特方式: 燃料电池。燃料电池类似于生物电池,因为电子也可以在分子之间来回转移。在这两种情况下,都会产生电和电。该研究指出,一个重要因素是地球在海底提供电能。“这种能量可以启动生命,并在其出现后维持生命。现在,我们有办法测试不同的材料和环境,这些材料和环境不仅可以帮助生命在地球上出现,而且可能在火星、欧罗巴和太阳系其他地方出现。”

[终译]2014年3月,美国国家航空和宇宙航行局的喷气推进实验室展示了一种研究生命起源的独特方式:燃料电池。燃料电池类似于生物电池,因为电子也可以在分子之间来回转移。在这两种情况下,都会产生电和能量。该研究指出,一个重要因素是地球在海底提供电能。“这种能量可以启动生命,并在其出现后维持生命。现在,我们有办法测试不同的材料和环境,这些材料和环境不仅可以帮助生命在地球上出现,而且可能在火星、木卫二和太阳系其他地方出现。”

Vesicles, micelles and membraneless droplets ==囊泡,微胶粒和无膜液滴

文件:Micelle scheme-en.svg
Scheme of a micelle spontaneously formed by phospholipids in an aqueous solution 磷脂在水溶液中自发形成的微胶粒图  

When phospholipids are placed in water, the molecules spontaneously arrange such that the tails are shielded from the water, resulting in the formation of membrane structures such as bilayers, vesicles, and micelles.[2] In modern cells, vesicles are involved in metabolism, transport, buoyancy control,[22] and enzyme storage. They can also act as natural chemical reaction chambers. A typical vesicle or micelle in aqueous solution forms an aggregate with the hydrophilic "head" regions in contact with surrounding solvent, sequestering the hydrophobic single-tail regions in the micelle centre. This phase is caused by the packing behavior of single-tail lipids in a bilayer. Although the protocellular self-assembly process that spontaneously form lipid monolayer vesicles and micelles in nature resemble the kinds of primordial vesicles or protocells that might have existed at the beginning of evolution, they are not as sophisticated as the bilayer membranes of today's living organisms.[23]

当磷脂被放置在水中时,分子会自动排列,使得尾部与水隔开,从而形成膜结构,如双层、小泡和微粒。在现代细胞中,囊泡参与新陈代谢、运输、浮力控制和酶储存。它们也可以作为天然的化学反应室。一个典型的囊泡或胶束在与周围的溶剂接触时形成一个亲水的“头部”区域的聚集体,在胶束中心隔离疏水的单尾区域。这个阶段是由双分子层中单尾脂质的堆积行为引起的。虽然自发形成类脂单层囊泡和胶束的原细胞自我组装过程类似于进化初期可能存在的原始囊泡或原始细胞,但它们并不像今天生物体的双层膜那样复杂。

[终译]当磷脂被放置在水中时,分子会自动排列,使得尾部与水隔开,从而形成膜结构,如双层、囊泡和微胶粒。在现代细胞中,囊泡参与新陈代谢、运输、浮力控制和酶储存。它们也可以作为天然的化学反应室。一个典型的囊泡或微胶粒在与周围的溶剂接触时形成一个亲水的“头部”区域的聚集体,在胶束中心隔离疏水的单尾区域。这个阶段是由双分子层中单尾脂质的堆积行为引起的。虽然自发形成类脂单层囊泡和微胶粒的原始细胞自我组装过程类似于进化初期可能存在的原始囊泡或原始细胞,但它们并不像现代生物的双层膜那样复杂。

Rather than being made up of phospholipids, however, early membranes may have formed from monolayers or bilayers of fatty acids, which may have formed more readily in a prebiotic environment.[24] Fatty acids have been synthesized in laboratories under a variety of prebiotic conditions and have been found on meteorites, suggesting their natural synthesis in nature.[4]

然而,早期的细胞膜可能不是由磷脂组成的,而是由脂肪酸的单层或双层形成的,这些脂肪酸可能在生命起源前的环境中更容易形成。脂肪酸已经在实验室合成的各种前生物条件下,并已在陨石上发现,表明他们在自然界中的自然合成。

[终译]然而,早期的细胞膜可能不是由磷脂组成的,而是由的单层或双层脂肪形成的,这些脂肪酸可能在生命起源前的环境中更容易形成。脂肪酸已经在实验室的各种前生物条件下合成出来,并已在陨石上发现,表明它们在自然界中能自然合成。

Oleic acid vesicles represent good models of membrane protocells that could have existed in prebiotic times.[25]

油酸囊泡代表了膜原始细胞的良好模型,这些细胞可能存在于生命起源之前的时代。

[终译]油酸囊泡代表了有膜原始细胞的优秀模型,这些细胞可能存在于生命起源之前的时代。

Electrostatic interactions induced by short, positively charged, hydrophobic peptides containing 7 amino acids in length or fewer, can attach RNA to a vesicle membrane, the basic cell membrane.[26][27]

短的、带正电荷的、含7个氨基酸或更少的疏水性肽引起的静电相互作用可以使 RNA 附着在囊泡膜上,囊泡膜是细胞的基本膜。

[终译]短的、带正电荷的、含7个氨基酸长度或更少的疏水性肽引起的静电相互作用可以使 RNA 附着在囊泡膜上,囊泡膜是细胞的基本膜。

Geothermal ponds and clay ==地热池和粘土

文件:Lipid bilayer section.gif
This fluid lipid bilayer cross section is made up entirely of phosphatidylcholine. 这个液体脂质双分子层的横截面完全由磷脂酰胆碱组成。  

Scientists have suggested that life began in hydrothermal vents in the deep sea, but a 2012 study suggests that inland pools of condensed and cooled geothermal vapor have the ideal characteristics for the origin of life.[28] The conclusion is based mainly on the chemistry of modern cells, where the cytoplasm is rich in potassium, zinc, manganese, and phosphate ions, which are not widespread in marine environments. Such conditions, the researchers argue, are found only where hot hydrothermal fluid brings the ions to the surface—places such as geysers, mud pots, fumaroles and other geothermal features. Within these fuming and bubbling basins, water laden with zinc and manganese ions could have collected, cooled and condensed in shallow pools.[28]

科学家认为生命起源于深海的热液喷口,但2012年的一项研究表明,内陆冷凝的地热蒸汽池具有生命起源的理想特征。这个结论主要是基于现代细胞的化学成分,细胞质中富含钾、锌、锰和磷酸根离子,这些在海洋环境中并不普遍。研究人员认为,只有在热水热流体将离子带到地表的地方才会发现这种情况,这些地方包括间歇泉、泥浆池、喷气孔和其他地热特征。在这些冒着气泡的盆子里,富含锌和锰离子的水可能聚集起来,冷却并凝结在浅水池中。

[终译]科学家认为生命起源于深海的热液喷口,但2012年的一项研究表明,内陆冷凝的地热蒸汽池具有生命起源的理想特征。这个结论主要是基于现代细胞的化学成分,细胞质中富含钾、锌、锰和磷酸根离子,这些在海洋环境中并不普遍。研究人员认为,只有在热水热流体将离子带到地表的地方才会发现这种情况,这些地方包括间歇泉、泥浆池、喷气孔和其他地热特征。在这些冒着气泡的盆中,富含锌和锰离子的水可能聚集起来,冷却并凝结在浅水池中。

Another study in the 1990s showed that montmorillonite clay can help create RNA chains of as many as 50 nucleotides joined together spontaneously into a single RNA molecule.[5] Later, in 2002, it was discovered that by adding montmorillonite to a solution of fatty acid micelles (lipid spheres), the clay sped up the rate of vesicle formation 100-fold.[5]

20世纪90年代的另一项研究表明,蒙脱石粘土可以帮助创建多达50个核苷酸自发连接成一个单一 RNA 分子的 RNA 链。后来,在2002年,人们发现在脂肪酸胶束(脂球)溶液中加入蒙脱石,粘土可以使囊泡的形成速度提高100倍。

[终译]20世纪90年代的另一项研究表明,蒙脱石粘土可以帮助创造一条由多达50个核苷酸自发连接成的单一RNA 分子的 RNA 链。后来,在2002年,人们发现在脂肪酸微胶粒(脂球)溶液中加入蒙脱石,粘土可以使囊泡的形成速度提高100倍。

Research has shown that some minerals can catalyze the stepwise formation of hydrocarbon tails of fatty acids from hydrogen and carbon monoxide gases—gases that may have been released from hydrothermal vents or geysers. Fatty acids of various lengths are eventually released into the surrounding water,[24] but vesicle formation requires a higher concentration of fatty acids, so it is suggested that protocell formation started at land-bound hydrothermal vents such as geysers, mud pots, fumaroles and other geothermal features where water evaporates and concentrates the solute.[5][29][30]

研究表明,一些矿物质可以催化氢气和一氧化碳气体中脂肪酸的碳氢化合物尾部逐步形成,这些气体可能是从热液喷口或间歇泉中释放出来的。不同长度的脂肪酸最终被释放到周围的水中,但是囊泡的形成需要更高浓度的脂肪酸,因此有人认为原始细胞的形成始于陆地上的热液喷口,如间歇泉、泥浆池、喷气孔和其他地热特征,在这些地方水蒸发和浓缩溶质。

[终译]研究表明,一些矿物可以催化氢气和一氧化碳气体逐步形成脂肪酸的碳氢化合物尾部,这些气体可能是从热液喷口或间歇泉中释放出来的。不同长度的脂肪酸最终被释放到周围的水中,但是囊泡的形成需要更高浓度的脂肪酸,因此有人认为原始细胞的形成始于陆地上的热液喷口,如间歇泉、泥浆池、喷气孔和其他地热特征,在这些地方蒸发水和浓缩溶质。

Montmorillonite bubbles ==蒙脱土气泡==

Another group suggests that primitive cells might have formed inside inorganic clay microcompartments, which can provide an ideal container for the synthesis and compartmentalization of complex organic molecules.[31] Clay-armored bubbles form naturally when particles of montmorillonite clay collect on the outer surface of air bubbles under water. This creates a semi permeable vesicle from materials that are readily available in the environment. The authors remark that montmorillonite is known to serve as a chemical catalyst, encouraging lipids to form membranes and single nucleotides to join into strands of RNA. Primitive reproduction can be envisioned when the clay bubbles burst, releasing the lipid membrane-bound product into the surrounding medium.[31]

另一个研究小组认为,原始细胞可能是在无机粘土微室中形成的,这种微室为复杂有机分子的合成和防火分区提供了理想的容器。当蒙脱石粘土颗粒聚集在水下气泡的外表面时,自然形成具有粘土铠甲结构的气泡。这样就创造了一个半渗透性小泡,其材料在环境中很容易获得。作者指出,蒙脱石被认为是一种化学催化剂,促进脂质形成膜,单核苷酸连接成 RNA 链。可以想象,当黏土泡泡破裂时,原始的繁殖过程,将脂膜结合的产物释放到周围的介质中。

[终译]另一个研究小组认为,原始细胞可能是在无机粘土微室中形成的,这种微室为复杂有机分子的合成和区室化提供了理想的容器。当蒙脱石粘土颗粒聚集在水下气泡的外表面时,自然形成具有粘土铠甲结构的气泡。这样就创造了一个半渗透性小泡,其材料在环境中很容易获得。作者指出,蒙脱石被认为是一种化学催化剂,促进脂质形成膜,单核苷酸连接成 RNA 链。可以想象,当黏土泡破裂时,原始的繁殖过程估计是将由脂膜结合的产物释放到周围的介质中。

Membraneless droplets ==无膜液滴==

Another way to form primitive compartments that may lead to the formation of a protocell is polyesters membraneless structures that have the ability to host biochemicals (proteins and RNA) and/or scaffold the assemblies of lipids around them.[32][33] While these droplets are leaky towards genetic materials, this leakiness could have facilitated the progenote hypothesis.[34]

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =.虽然这些液滴是漏向遗传物质的,这种漏洞可能促进了原子假说。

[终译]形成原始细胞隔室进而形成原始细胞的另一种途径是聚酯无膜结构,这种结构具有容纳生物化学物质(蛋白质和RNA)和/或在其周围构建脂质组件的能力。虽然这些液滴是漏向遗传物质的,但这种漏洞可能促进了始祖生物假说。

Membrane transport ==膜转运==

文件:Pore schematic.svg
Schematic showing two possible conformations of the lipids at the edge of a pore. In the top image the lipids have not rearranged, so the pore wall is hydrophobic. In the bottom image some of the lipid heads have bent over, so the pore wall is hydrophilic.孔隙边缘脂质的两种可能构象的图示。 在上图中,脂质没有重新排列,因而孔壁是疏水的。 在下图中,一些脂质头已经弯曲,因而孔壁是亲水的。  

For cellular organisms, the transport of specific molecules across compartmentalizing membrane barriers is essential in order to exchange content with their environment and with other individuals. For example, content exchange between individuals enables horizontal gene transfer, an important factor in the evolution of cellular life.[35] While modern cells can rely on complicated protein machineries to catalyze these crucial processes, protocells must have accomplished this using more simple mechanisms.

这张图片展示了两种可能存在于孔隙边缘的脂类膜输送。在上图中,油脂没有重新排列,所以孔壁是疏水的。在底部的图像中,一些脂头已经弯曲,所以孔壁是亲水的。对于细胞生物来说,特定的分子通过隔膜屏障的运输是必不可少的,以便与其环境和其他个体交换内容。例如,个体之间的内容交换可以产生基因水平转移,这是细胞生命进化的一个重要因素。虽然现代细胞可以依靠复杂的蛋白质机制来催化这些关键过程,但原始细胞必须使用更简单的机制来完成这些过程。

[终译]对于细胞生物来说,特定的分子通过隔膜屏障的运输是必不可少的,以便与其环境和其他个体交换内容。例如,个体之间的内容交换可以产生基因水平转移,这是细胞生命进化的一个重要因素。虽然现代细胞可以依靠复杂的蛋白质机制来催化这些关键过程,但原始细胞必须使用更简单的机制来完成这些过程。

Protocells composed of fatty acids[36] would have been able to easily exchange small molecules and ions with their environment.[1] Membranes consisting of fatty acids have a relatively high permeability to molecules such as nucleoside monophosphate (NMP), nucleoside diphosphate (NDP), and nucleoside triphosphate (NTP), and may withstand millimolar concentrations of Mg2+.[37] Osmotic pressure can also play a significant role regarding this passive membrane transport.[1]

由脂肪酸组成的原始细胞能够很容易地与环境中的小分子和离子进行交换。由脂肪酸组成的膜对核苷一磷酸(NMP)、核苷二磷酸(NDP)和核苷三磷酸(NTP)等分子具有较高的渗透性,并且可以承受一定浓度的 Mg2 + 。渗透压也可以在这种被动的膜输送中扮演重要的角色。

[终译]由脂肪酸组成的原始细胞能够很容易地与环境中的小分子和离子进行交换。由脂肪酸组成的膜对核苷一磷酸(NMP)、核苷二磷酸(NDP)和核苷三磷酸(NTP)等分子具有较高的渗透性,并且可以承受一定浓度的 Mg2+ 。渗透压也可以在这种膜被动运输中扮演重要的角色。

Environmental effects have been suggested to trigger conditions under which a transport of larger molecules, such as DNA and RNA, across the membranes of protocells is possible. For example, it has been proposed that electroporation resulting from lightning strikes could enable such transport.[38] Electroporation is the rapid increase in bilayer permeability induced by the application of a large artificial electric field across the membrane. During electroporation, the lipid molecules in the membrane shift position, opening up a pore (hole) that acts as a conductive pathway through which hydrophobic molecules like nucleic acids can pass the lipid bilayer.[39] A similar transfer of content across protocells and with the surrounding solution can be caused by freezing and subsequent thawing. This could, for instance, occur in an environment in which day and night cycles cause recurrent freezing. Laboratory experiments have shown that such conditions allow an exchange of genetic information between populations of protocells.[40] This can be explained by the fact that membranes are highly permeable at temperatures slightly below their phase transition temperature. If this point is reached during the freeze-thaw cycle, even large and highly charged molecules can temporarily pass the protocell membrane.

环境效应已经被认为可以触发更大的分子,如 DNA 和 RNA,通过原始细胞膜传输的条件。例如,有人提出,雷击产生的电穿孔可以使这种迁移成为可能。电穿孔是在膜上施加大量人工电场引起的双层膜通透性的快速增加。在电穿孔过程中,膜上的脂质分子移动位置,打开一个孔,作为导电通道,像核酸这样的疏水分子可以通过这个孔通过脂质双分子层。在原细胞之间以及与周围溶液的相似的内容转移可以由冻结和后续解冻引起。例如,这可能发生在白天和夜晚周期导致反复冻结的环境中。实验室实验表明,这种条件允许原始细胞群体之间交换遗传信息。这可以解释为膜在略低于其相变温度的温度下具有高透水性。如果在冻融循环中达到这一点,即使是大的高电荷分子也可以暂时通过原细胞膜。

[终译]环境效应被认为是触发较大分子运输的条件,如 DNA 和 RNA,通过原始细胞的膜是可能的。例如,有人提出,雷击产生的电穿孔可以使这种迁移成为可能。电穿孔是在膜上施加大量人工电场引起的双层膜通透性的快速增加。在电穿孔过程中,膜上的脂质分子移动位置,打开一个孔,作为导电通道,像核酸这样的疏水分子可以通过这个孔通过脂质双分子层。在原始细胞之间以及与周围溶液的相似的内容转移可以由冻结和后续解冻引起。例如,这可能发生在白天和夜晚的周期性导致的反复冻结的环境中。实验室实验表明,这种条件允许原始细胞群体之间交换遗传信息。这可以解释为膜在略低于其相变温度的温度下具有高透水性。如果在冻融循环中达到这一点,即使是大的高电荷分子也可以暂时通过原始细胞膜。

Some molecules or particles are too large or too hydrophilic to pass through a lipid bilayer even under these conditions, but can be moved across the membrane through fusion or budding of vesicles,[41] events which have also been observed for freeze-thaw cycles.[42] This may eventually have led to mechanisms that facilitate movement of molecules to the inside of the protocell (endocytosis) or to release its contents into the extracellular space (exocytosis).[41]

有些分子或颗粒太大或太亲水,即使在这种情况下也不能通过脂双分子层,但是可以通过囊泡的融合或出芽穿过膜,这种情况在冻融循环中也可以观察到。这可能最终导致了促进分子运动到原始细胞内部的机制(内吞作用) ,或者将其内容物释放到细胞外液中(胞外作用)。

[终译]有些分子或颗粒太大或太亲水以至于也不能通过脂双分子层,但是可以通过囊泡的融合或出芽穿过膜,这种情况在冻融循环中也可以观察到。这可能最终导致了促进分子运动到原始细胞内部的机制(胞吞作用) ,或者将其内容物释放到细胞外液中(胞吐作用)。

Sexual reproduction = = 有性生殖 = =

Eigen et al.[43] and Woese[44] proposed that the genomes of early protocells were composed of single-stranded RNA, and that individual genes corresponded to separate RNA segments, rather than being linked end-to-end as in present-day DNA genomes. A protocell that was haploid (one copy of each RNA gene) would be vulnerable to damage, since a single lesion in any RNA segment would be potentially lethal to the protocell (e.g. by blocking replication or inhibiting the function of an essential gene).

= = 有性生殖 = = Eigen et al. 。及 WoeseWoese CR (1983)。世系的基本线和普遍祖先。第二章。209-233.提出早期原始细胞的基因组是由单链 RNA 组成的,个体基因对应于单独的 RNA 片段,而不是像现在的 DNA 基因组那样端对端连接。单倍体的原始细胞(每个 RNA 基因的一个拷贝)容易受到损伤,因为任何 RNA 片段中的单个损伤都可能对原始细胞致死(例如:。通过阻止复制或抑制必需基因的功能)。

[终译]Eigen及Woese等人提出早期原始细胞的基因组是由单链 RNA 组成的,每个基因对应于单独的 RNA 片段,而不是像现在的 DNA 基因组那样端对端连接。单倍体的原始细胞(每个 RNA 基因只有一个拷贝)容易受到损伤,因为任何 RNA 片段中的单个损伤都可能对原始细胞致死(例如:通过阻止复制或抑制必需基因的功能)。

Vulnerability to damage could be reduced by maintaining two or more copies of each RNA segment in each protocell, i.e. by maintaining diploidy or polyploidy. Genome redundancy would allow a damaged RNA segment to be replaced by an additional replication of its homolog. However, for such a simple organism, the proportion of available resources tied up in the genetic material would be a large fraction of the total resource budget. Under limited resource conditions, the protocell reproductive rate would likely be inversely related to ploidy number. The protocell's fitness would be reduced by the costs of redundancy. Consequently, coping with damaged RNA genes while minimizing the costs of redundancy would likely have been a fundamental problem for early protocells.

保持每个原始细胞中每个 RNA 片段的两个或两个以上拷贝,可以降低受损害的脆弱性。保持二倍性或多倍性。基因组冗余将使受损的 RNA 片段被其同源基因的额外复制所取代。然而,对于这样一个简单的生物体而言,与遗传材料有关的可用资源的比例将占资源总预算的很大一部分。在有限的资源条件下,原细胞的繁殖率可能与倍性数成反比。原始细胞的适应性会因冗余成本而降低。因此,在处理受损的 RNA 基因的同时尽量减少冗余成本可能是早期原始细胞的一个基本问题。

[终译]保持每个原始细胞中每个 RNA 片段有两个或两个以上拷贝,可以降低受损害的脆弱性,即保持二倍性或多倍性。基因组冗余将使受损的 RNA 片段被其同源基因的额外复制所取代。然而,对于这样一个简单的生物体而言,与遗传材料有关的可用资源的比例将占资源总预算的很大一部分。在有限的资源条件下,原始细胞的繁殖率可能与倍型数量成反比。原始细胞的适应性会因冗余成本而降低。因此,在处理受损的 RNA 基因的同时尽量减少冗余成本可能是早期原始细胞的一个基本问题。

A cost-benefit analysis was carried out in which the costs of maintaining redundancy were balanced against the costs of genome damage.[45] This analysis led to the conclusion that, under a wide range of circumstances, the selected strategy would be for each protocell to be haploid, but to periodically fuse with another haploid protocell to form a transient diploid. The retention of the haploid state maximizes the growth rate. The periodic fusions permit mutual reactivation of otherwise lethally damaged protocells. If at least one damage-free copy of each RNA gene is present in the transient diploid, viable progeny can be formed. For two, rather than one, viable daughter cells to be produced would require an extra replication of the intact RNA gene homologous to any RNA gene that had been damaged prior to the division of the fused protocell. The cycle of haploid reproduction, with occasional fusion to a transient diploid state, followed by splitting to the haploid state, can be considered to be the sexual cycle in its most primitive form.[45][46] In the absence of this sexual cycle, haploid protocells with damage in an essential RNA gene would simply die.

实施了一项成本-收益分析计划,其中维持冗余的成本与基因组损坏的成本相平衡。这项分析得出的结论是,在大范围的环境下,选择的策略是使每个原始细胞成为单倍体,但是定期与另一个单倍体细胞融合,形成一个暂时的二倍体。单倍体状态的保持使生长率最大化。这种周期性的融合允许原始细胞的相互重新激活,否则原始细胞就会遭到致命的破坏。如果每个 RNA 基因在瞬时二倍体中至少存在一个无损伤拷贝,则可形成有活力的后代。对于两个,而不是一个,可行的子细胞将需要额外的复制完整的 RNA 基因的同源 RNA 基因的任何 RNA 基因已经受损前的融合原细胞分裂。单倍体的繁殖周期,偶尔融合到短暂的二倍体状态,然后分裂到单倍体状态,可以被认为是最原始形式的性周期。参见 pgs。293-297如果没有这种有性周期,单倍体原始细胞如果在核糖核酸基因上有损伤,就会死亡。

[终译]进行了成本效益分析,其中保持冗余的成本与基因组损伤的成本相平衡。这一分析得出的结论是,在各种各样的情况下,选择的策略是每个原始细胞成为单倍体,但周期性地与另一个单倍体原始细胞融合形成暂时的二倍体。单倍体状态的保持使生长率最大化。这种周期性的融合使得原本受致命损害的原始细胞能够相互重新激活。如果每个RNA基因至少有一个无损伤拷贝存在于瞬时二倍体中,就可以形成有活力的后代。为了产生两个而不是一个有活力的子细胞,需要额外复制完整的RNA基因,该RNA基因与在融合的原始细胞分裂之前被破坏的任何RNA基因同源。单倍体的繁殖周期,偶尔融合成短暂的二倍体状态,然后分裂成单倍体状态,可以被认为是最原始形式的性周期。如果没有这种性周期,单倍体原始细胞只要有一个必需的RNA基因受损,就会死亡。

This model for the early sexual cycle is hypothetical, but it is very similar to the known sexual behavior of the segmented RNA viruses, which are among the simplest organisms known. Influenza virus, whose genome consists of 8 physically separated single-stranded RNA segments,[47] is an example of this type of virus. In segmented RNA viruses, "mating" can occur when a host cell is infected by at least two virus particles. If these viruses each contain an RNA segment with a lethal damage, multiple infection can lead to reactivation providing that at least one undamaged copy of each virus gene is present in the infected cell. This phenomenon is known as "multiplicity reactivation". Multiplicity reactivation has been reported to occur in influenza virus infections after induction of RNA damage by UV-irradiation,[48] and ionizing radiation.[49]

这个关于早期性周期的模型是假设的,但是它与已知的分节 RNA 病毒的性行为非常相似,这种病毒是已知的最简单的生物体之一。流感病毒就是这类病毒的一个例子,它的基因组由8个物理分离的单链 RNA 片段组成。在分节 RNA 病毒中,当宿主细胞被至少两种病毒颗粒感染时,就会发生“交配”。如果这些病毒每一个都含有一个具有致命损伤的 RNA 片段,如果每个病毒基因的至少一个未受损的拷贝存在于被感染的细胞中,多重感染可导致重新激活。这种现象被称为“多重复激活”。据报道,在流感病毒感染中,紫外线和电离辐射辐射诱导 RNA 损伤后会发生多重再激活。

[终译]这个关于早期性周期的模型是假设的,但是它与已知的分节 RNA 病毒的性行为非常相似,这种病毒是已知的最简单的生物体之一。流感病毒就是这类病毒的一个例子,它的基因组由8个物理分离的单链 RNA 片段组成。在分节RNA病毒中,当宿主细胞被至少两种病毒颗粒感染时,就会发生“交配”。如果这些病毒每一个都含有一个具有致命损伤的RNA片段,如果每个病毒基因的至少一个未受损的拷贝存在于被感染的细胞中,多重感染就可以导致重新激活。这种现象被称为“多重性再激活”。据报道,在流感病毒感染中,紫外线和电离辐辐射诱导 RNA 损伤后会发生多重再激活。

Artificial models = =人工模型 = =

Langmuir-Blodgett deposition = = 朗缪尔-布洛杰特沉积 = =

Starting with a technique commonly used to deposit molecules on a solid surface, Langmuir–Blodgett deposition, scientists are able to assemble phospholipid membranes of arbitrary complexity layer by layer.[50][51] These artificial phospholipid membranes support functional insertion both of purified and of in situ expressed membrane proteins.[51] The technique could help astrobiologists understand how the first living cells originated.[50]

= = = 朗缪尔-布洛杰特沉积 = = = 从一种通常用于在固体表面沉积分子的技术——朗缪尔-布洛杰特沉积开始,科学家们能够一层一层地组装任意复杂的磷脂膜。这些人工磷脂膜支持功能插入纯化和原位表达膜蛋白。这项技术可以帮助天体生物学家理解第一个活细胞是如何起源的。

[终译]从常用于在固体表面沉积分子的技术——朗缪尔-布洛杰特沉积开始,科学家们能够一层一层地组装任意复杂程度的磷脂膜。这些人工磷脂膜支持纯化的和原位表达的膜蛋白的功能性插入。这项技术可以帮助天体生物学家理解第一个活细胞是如何起源的。

Jeewanu protocells ==Jeewanu原始细胞==

文件:Surfactant.jpg
Surfactant molecules arranged on an air – water interface 在空气-水界面上排列的表面活性剂分子  


thumb|left|150px|Surfactant molecules arranged on an air – water interface

= = = = = 拇指 | 左边 | 150px | 表面活性剂分子排列在气-水界面上

[终译]拇指 | 左边 | 150px(像素单位) | 表面活性剂分子排列在空气-水界面上

Jeewanu protocells are synthetic chemical particles that possess cell-like structure and seem to have some functional living properties.[52] First synthesized in 1963 from simple minerals and basic organics while exposed to sunlight, it is still reported to have some metabolic capabilities, the presence of semipermeable membrane, amino acids, phospholipids, carbohydrates and RNA-like molecules.[52][53] However, the nature and properties of the Jeewanu remains to be clarified.[52][53][54]

Jeewanu 原始细胞是合成的化学颗粒,具有细胞样结构,似乎具有一些功能性的活性。1963年首次在阳光下由简单矿物质和基本有机物合成,据报道它仍然具有一些新陈代谢能力,包括半透膜、氨基酸、磷脂、碳水化合物和类 rna 分子。然而,Jeewanu 的性质和属性仍有待澄清。

[终译]Jeewanu原始细胞是合成的化学粒子,具有细胞样结构,似乎具有一些功能性的生命属性。首次合成于1963年,由暴露于阳光下的简单矿物质和基本有机物合成,据报道它仍具有一些代谢能力,包括半透膜、氨基酸、磷脂、碳水化合物和类RNA分子。然而,Jeewanu的性质和属性仍有待澄清。

In a similar synthesis experiment a frozen mixture of water, methanol, ammonia and carbon monoxide was exposed to ultraviolet (UV) radiation. This combination yielded large amounts of organic material that self-organised to form globules or vesicles when immersed in water.[55] The investigating scientist considered these globules to resemble cell membranes that enclose and concentrate the chemistry of life, separating their interior from the outside world. The globules were between 模板:Convert, or about the size of red blood cells. Remarkably, the globules fluoresced, or glowed, when exposed to UV light. Absorbing UV and converting it into visible light in this way was considered one possible way of providing energy to a primitive cell. If such globules played a role in the origin of life, the fluorescence could have been a precursor to primitive photosynthesis. Such fluorescence also provides the benefit of acting as a sunscreen, diffusing any damage that otherwise would be inflicted by UV radiation. Such a protective function would have been vital for life on the early Earth, since the ozone layer, which blocks out the sun's most destructive UV rays, did not form until after photosynthetic life began to produce oxygen.[56]


在一个类似的合成实验中,将水、甲醇、氨和一氧化碳的混合物冻结在紫外线(UV)辐射下。这种结合产生了大量的有机物质,自我组织形成小球或小泡当浸泡在水中。这位科学家认为这些小球类似于细胞膜,包裹并集中了生命的化学成分,将其内部与外部世界分开。这些小球介于两者之间,大约相当于红细胞的大小。值得注意的是,当暴露在紫外线下时,这些小球会发出荧光或发光。以这种方式吸收紫外线并将其转化为可见光被认为是向原始细胞提供能量的一种可能方式。如果这些小球在生命起源中起了作用,那么荧光可能是原始光合作用的前兆。这种荧光还提供了作为防晒剂的好处,扩散任何损害,否则将造成的紫外线辐射。这种保护功能对早期地球上的生命至关重要,因为臭氧层阻挡了太阳最具破坏性的紫外线,直到光合作用生命开始产生氧气后才形成。

[终译]在一个类似的合成实验中,将水、甲醇、氨和一氧化碳的冷冻混合物暴露在紫外线(UV)辐射下。这种结合产生了大量的有机物质,当浸入水中时,它们自组织形成液滴或囊泡。进行研究的科学家认为这些小球类似于细胞膜,包裹并浓缩了生命的化学物质,将它们的内部与外界隔开。这些小球介于或大约与红细胞一样大。值得注意的是,当暴露在紫外光下时,这些小球会发出荧光或发光。以这种方式吸收紫外线并将其转化为可见光被认为是向原始细胞提供能量的一种可能方式。如果这些小球在生命起源中发挥了作用,那么荧光可能是原始光合作用的前兆。这种荧光还提供了作为防晒剂的好处,缓解了会由紫外线辐射造成的任何损害。这种保护功能对早期地球上的生命至关重要,因为臭氧层阻挡了太阳最具破坏性的紫外线,直到光合生命开始产生氧气后才形成。

Bio-like structures = = 生物样结构 = =

The synthesis of three kinds of "jeewanu" have been reported; two of them were organic, and the other was inorganic. Other similar inorganic structures have also been produced. The investigating scientist (V. O. Kalinenko) referred to them as "bio-like structures" and "artificial cells". Formed in distilled water (as well as on agar gel) under the influence of an electric field, they lack protein, amino acids, purine or pyrimidine bases, and certain enzyme activities. According to NASA researchers, "presently known scientific principles of biology and biochemistry cannot account for living inorganic units" and "the postulated existence of these living units has not been proved".[54]

= = = 生物样结构 = = 报道了三种“ jeewanu”的合成,其中两种为有机结构,另一种为无机结构。其他类似的无机结构也已经产生。调查科学家(V.o. 卡里年科)称之为“生物样结构”和“人造细胞”。它们在蒸馏水中(以及在琼脂凝胶上)在电场的影响下形成,缺乏蛋白质、氨基酸、嘌呤或嘧啶碱基和某些酶活性。根据美国航天局的研究人员,”目前已知的生物学和生物化学科学原理不能解释活的无机单位”和”这些生物单位的假设存在尚未得到证明”。

[终译]三种“ jeewanu”的合成被报道,其中两种为有机结构,另一种为无机结构。其他类似的无机结构也已经产生。调查科学家V.O.卡里年科称之为“生物样结构”和“人造细胞”。它们在蒸馏水中(以及在琼脂凝胶上)在电场的影响下形成,缺乏蛋白质、氨基酸、嘌呤或嘧啶碱基和某些酶活性。根据美国航天局的研究人员所述,“目前已知的生物学和生物化学科学原理不能解释活的无机单位”,“这些生物单位的假定存在尚未得到证明”。

Ethics and controversy ==伦理和争论==

Protocell research has created controversy and opposing opinions, including critics of the vague definition of "artificial life".[57] The creation of a basic unit of life is the most pressing ethical concern, although the most widespread worry about protocells is their potential threat to human health and the environment through uncontrolled replication.[58]

原细胞研究引起了争议和反对意见,包括对”人工生命”的模糊定义的批评。创造生命的基本单位是最紧迫的伦理问题,尽管人们最普遍的担心是原始细胞通过不受控制的复制对人类健康和环境的潜在威胁。

[终译]原始细胞研究已经引起了争论和反对意见,包括对“人工生命”的模糊定义的批评。尽管人们最普遍的担心是原始细胞通过不受控制的复制对人类健康和环境产生潜在威胁,但生命基本单位的创造是最亟待解决的伦理问题。

See also


  • Protocell Circus, a film
  • Pseudo-panspermia


See also

  • Protocell Circus, a film
  • Pseudo-panspermia

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  58. Bedau, Mark A.; Parke, Emily C. (2009). The ethics of protocells moral and social implications of creating life in the laboratory (Online ed.). Cambridge, MA: MIT Press. ISBN 978-0-262-51269-5. 

External links

  • "Protocells: Bridging Nonliving and Living Matter." Edited by Steen Rasmussen, Mark A. Bedau, Liaochai Chen, David Deamer, David Krakauer, Norman, H.Packard and Peter F. Stadler. MIT Press, Cambridge, Massachusetts. 2008.
  • "Living Chemistry & A Natural History of Protocells." Synth-ethic: Art and Synthetic Biology Exhibition (2013) at the Natural History Museum, Vienna, Austria.
  • Kenyon, DH; Nissenbaum, A (Apr 1976). "Melanoidin and aldocyanoin microspheres: implications for chemical evolution and early precambrian micropaleontology". J. Mol. Evol. 7 (3): 245–51. Bibcode:1976JMolE...7..245K. doi:10.1007/bf01731491. PMID 778393. S2CID 2995886.

模板:Origin of life 模板:Biology nav 模板:Self-replicating organic structures 模板:Organisms et al. 模板:Portal bar

  • "Protocells: Bridging Nonliving and Living Matter." Edited by Steen Rasmussen, Mark A. Bedau, Liaochai Chen, David Deamer, David Krakauer, Norman, H.Packard and Peter F. Stadler. MIT Press, Cambridge, Massachusetts. 2008.
  • "Living Chemistry & A Natural History of Protocells." Synth-ethic: Art and Synthetic Biology Exhibition (2013) at the Natural History Museum, Vienna, Austria.




= = = 外部链接 = =”原细胞: 连接无生命物质和生命物质”编辑: Steen Rasmussen,Mark a. Bedau,liao chai Chen,David Deamer,David Krakauer,Norman,h. packard and Peter f. Stadler。麻省理工出版社,剑桥,马萨诸塞州。2008.

  • 「活化学 & 原始细胞自然史」合成生物学: 艺术与合成生物学展(2013年) ,奥地利维也纳自然历史博物馆。

Category:Evolutionarily significant biological phenomena Category:Evolutionary biology Category:Membrane biology Category:Origin of life Category:Synthetic biology Category:Prebiotic chemistry

类别: 进化意义重大的生物现象类别: 进化生物学类别: 膜生物学类别: 生命起源类别: 合成生物学类别: 前生命化学


This page was moved from wikipedia:en:Protocell. Its edit history can be viewed at Protocell/edithistory