Chemical Routes to Primitive Membranes: Prebiotic Lipid Formation at the Origin of Life.

The origin of life is, to the best of our knowledge, impossible to imagine without the formation of complex prebiotic biomolecules such as RNA, DNA, proteins and lipids. Lipids play a crucial role in the spontaneous formation of cell membranes, which are responsible for cell integrity, compartmentalization, selective permeability, and providing a microenvironment for biochemical reactions. The goal of the current work is to summarize the current state of the art regarding the abiotic formation of membrane building blocks, such as glycerol, fatty acids, and their phosphorylated version as phospholipid precursors. We describe the necessity of a systems chemistry approach for the complexification and expansion of the prebiotic network, enabling the formation of several membranogenic precursors. We also discuss prebiotic pathways for phosphorylation and acylation that could lead to phospholipid availability in hydrothermal environments and on the early Earth surface. We conclude with the possible spontaneous vesiculation of these molecules as a primitive version of the cell membrane. Thus, we present a comprehensive perspective on prebiotic vesicle formation, starting from simple molecules and developing until the self-assembly of vesicles.