SYMMETRY BREAKING IS THE PHYSICAL BASIS FOR THE PERFORMANCE OF "USEFUL WORK" BY BIOLOGICAL MOLECULAR MACHINES

Abstract

The physical basis for the functioning of living systems are molecular machines. The performance of "useful work" is the essence of their biological functions. Molecular machines are chiral hierarchically organized devices (constructions). They cyclically transform the form of energy by changing or switching symmetries in its chiral structural elements, which just realize the selected “quasi-mechanical” degrees of freedom in them. The phenomenon of chirality allows the formation of discrete chirally sign-alternating hierarchies of structures in macromolecular machines in the process of folding: starting from the level of asymmetric carbon in deoxyribose and amino acids. Previously, we have identified and analyzed the tendency of alternation of the sign of chirality of the intramolecular structural levels D-L-D-L for DNA and L-D-L-D for proteins. Helicity and superhelicity of intramolecular and supramolecular structures are also manifestations of chirality. Also, within the framework of the developed ideas, the chiral splitting of the properties of the elements of the structures ensures the unidirectional movement of machines along the energy cycle due to the nonlinear valve properties of the spiral structures. Spiral structures can serve as asymmetric, non-linear, mechanical, including switching, structural elements of molecular machines (like a ratchet-pawl device) in terms of rotational degrees of freedom.