Chirality and the Origins of Life

Abstract

Molecular asymmetry is examined in present life, and in prebiotic systems. The origin of chirality has been ascribed to a chance choice of the initial enantiomer or to a universal disymmetric force. The weak neutral current of the electro weak interaction provides a constant and uniform chiral agency which favors both L-amino acids and D-sugars. Amplification of a small excess in one enantiomer can be achieved in open systems far from equilibrium, by crystallization or via ordered structures of biopolymers. A tentative coherent approach to the problem of chirality in the course of evolution is presented in the form of an integrated model which includes all of the main homochiral biomolecular families (amino acids, sugars, lipids).