Pre-cell

A pre-cell 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. 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.