Biological macromolecules as gels: functional similarities.

Functional biological macromolecules arising from folding, cross-connection, and solvation of long-chain biopolymers forming three-dimensional networks can be compared to gels. Both involve identical internal competitive forces that are selectively influenced by external conditions and conspire to adjust conformations and modulate functions. In spite of important differences in size, chemical composition, polymer density, and configuration, biological macromolecules indeed manifest some of the essential physical-chemical properties of gels. This result represents presumptive evidence for common underlying mechanisms in functional molecules and gels. Thus, the present and highly perfectible model explains why and how, depending on initial conditions, a system may respond differently to an external parameter and similarly to different parameters. Moreover, the fact that any localized change in one of the competitive forces gives rise to a pressure in the system as a whole provides one explanation for the mechanism of the transmission of information.