Redox Directionality as the Origin of Biological Chirality: A Symmetry-Breaking Mechanism Emerging from the Proto-Liver Origin of Life (PLOL) Model

Life on Earth universally employs L-amino acids, D-sugars, and right-handed DNA helices, yet the physical mechanism that first selected and fixed these molecular asymmetries remains unresolved.
This paper proposes a novel solution: directional redox flow in a prebiotic regulator-first environment—the Proto-Liver Origin of Life (PLOL) framework—served as the original symmetry-breaking mechanism responsible for biological chirality.
Sunlight-driven redox gradients in mineral–water interfaces create anisotropic electron and proton flows, preferentially stabilizing one enantiomeric family over the other. Repeated wet–dry and thermal cycles amplify this preference, producing homochiral monomers that polymerize into helices whose handedness is geometrically determined by monomer chirality.
This model explains the universality of biological chirality and identifies DNA’s right-handed twist as a downstream structural consequence of early redox directionality. The hypothesis generates clear, testable predictions and integrates metabolic, structural, and informational aspects of molecular evolution.