Pre-cell

A pre-cell (or protocell) is a hypothetical lipid-based structure that, under the RNA world hypothesis, could have confined RNA in ancient times. A pre-cell allowed the RNA to remain in close proximity with other RNA molecules, keeping them concentrated and allowing for an increased reaction rate of enzymes.[1] Pre-cells would have had semi-permeable membranes, allowing only certain molecules to pass through. These enclosed structures may have facilitated natural selection in RNA molecules.

Structure

Pre-cells are thought to have had a membrane composed of mixed-enantiomer lipid molecules. As natural selection proceeded, pre-cells may have developed stereospecific lipid membranes through frequent fission and fusion of racemic pre-cells.[2]

References
  1. Black, S (May 23, 1970). "Pre-cell evolution and te origin of enzymes". Nature. 226 (5247): 754–5. doi:10.1038/226754a0. PMID 5443250.
  2. Wächtershäuser, G (January 2003). "From pre-cells to Eukarya--a tale of two lipids". Molecular Microbiology. 47 (1): 13–22. doi:10.1046/j.1365-2958.2003.03267.x. PMID 12492850. S2CID 37944519.


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