While great progress has been made over the last hundred years in the characterization of the molecular constituents of biological systems and their grouping into classes such as nucleotides, proteins, polysaccharides and lipids, how these components conspire in order to yield systems with manifest biological function is not, in general, well understood. Nowhere is this shortfall more evident than in cases where the emergent functionality is the control of materials properties as epitomized by the role of the biopolymer matrix in the plant cell wall.
In this case, it is known that polysaccharides play a major role in satisfying the mechanical requirements of a successful cell, but developing a clear structure-function understanding is exacerbated by the fact that the relevant polysaccharide architecture is itself heterogeneous and complex. Ongoing work in this area is aimed at the controlled molecular engineering of polysaccharide structures, and the development of novel measurement techniques for fine structure elucidation, in order to facilitate the construction of well-defined model systems.
The functionality of such biopolymers is subsequently investigated; for example by using the atomic force microscope and optical tweezers in order to stretch single polymeric molecules and thereby measure the nanomechanical properties of individual chains. In addition soft materials are being constructed by the controlled assembly of the polymers and the resulting network properties examined within the experimental and theoretical framework of soft condensed matter physics.