• Azotosome


    • An azotosome (classical compound of "azote", French for nitrogen, and "soma", Greek for body) is a theoretical membrane that could possibly serve as the basis for a cell membrane of a hypothetical methaneethane-based living cell, analogous to the phospholipid bilayers found in all water-based life on Earth. Unlike a phospholipid-based cell membrane, an azotosome is composed of chemicals found in the methane–ethane liquid seas and in the atmosphere of Saturn's moon Titan, and it is capable of functioning in these conditions as a membrane. Thus far, azotosomes have only been computationally modeled, and have not been observed experimentally.

      The azotosome was proposed in February 2015 by researchers at Cornell University based on computer modeling of theoretical membrane structures. The researchers claimed to be inspired in part by science fiction writer Isaac Asimov's 1962 essay about the concept of non-water based life, entitled "Not as we know it".

      In principle, the term azotosome refers to any membrane composed of nitrogen, carbon, and hydrogen. The most stable azotosome yet modeled is composed of acrylonitrile, a small molecule composed of three carbons, three hydrogens, and one nitrogen atom. Compared to phospholipids, which make up cell membranes found in life on Earth, acrylonitrile is very small and simple. In the proposed azotosome, acrylonitrile molecules are not arranged in two layers with a hydrophobic and hydrophilic side; rather, some of them are arranged with their nitrogen facing inward and others with their nitrogen facing outward. Despite these differences from phospholipid membranes, the acrylonitrile azotosome is stable, a strong barrier to decomposition, and has a flexibility similar to that of phospholipid membranes. Acrylonitrile is present at 10 parts per million in Titan's atmosphere and is theorized to self-assemble into azotosomes in the cryogenic liquid methane environment of Titan's seas.

  • What Else?

    • Azotosome