The environmental and chemical limits of life are two of the most central questions in astrobiology. Our understanding of life's boundaries has implications on the efficacy of biosignature identification in exoplanet atmospheres and in the solar system. The lipid bilayer membrane is one of the central prerequisites for life as we know it. Previous studies based on molecular dynamics simulations have suggested that polarity-inverted membranes, azotosomes, made up of small nitrogen-containing molecules, are kinetically persistent and may function on cryogenic liquid hydrocarbon worlds, such as Saturn's moon Titan. We here take the next step and evaluate the thermodynamic viability of azotosome formation. Quantum mechanical calculations predict that azotosomes are not viable candidates for self-assembly akin to lipid bilayers in liquid water. We argue that cell membranes may be unnecessary for hypothetical astrobiology under stringent anhydrous and low-temperature conditions akin to those of Titan.

中文翻译：

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极性反转膜可以在Titan上自组装吗？

生命的环境和化学极限是天体生物学中最重要的两个问题。我们对生命边界的理解对系外行星大气和太阳系中生物特征识别的有效性产生了影响。众所周知，脂质双层膜是生命的核心前提之一。先前基于分子动力学模拟的研究表明，极性反转的膜（由小分子含氮分子组成）具有一定的动力学持久性，并且可能在低温液态烃世界（如土星的月亮泰坦）中起作用。我们在这里进行下一步，评估偶氮小体形成的热力学可行性。量子力学计算预测，类似于液体水中的脂质双层，偶氮小体不是可行的自组装候选物。