The Context

 

Exploring the physics underlying biological processes in the cell

Nano Bio Science is the term that best defines the research context of our laboratory. We are working in the field of Molecular and Cell Biophysics, furthering the study of the macromolecules that make up the machinery of cells. Our laboratory attempts to increase our understanding of the molecules of life beyond the biochemical viewpoint.

 

Biological molecules have traditionally been studied with bulk biochemical methods, where a large number of molecules are analysed simultaneously. These macroscopic experiments provide ensemble and time averages of the individual characteristics of each molecule. The set of deterministic properties and slow variation thus obtained results in an idealised image, that is, molecules with slow and well defined dynamics.

 

The single molecule analysis and the physics of mesoscopic systems

The picture is very different at the level of the individual molecule: one can find it in states that are far from the average behaviour of the population, and their instantaneous dynamics are rapid and highly random. At this level of detail, a mesoscopic description becomes necessary. Single-molecule experiments differ from macroscopic measurements in two fundamental aspects. First, the importance of fluctuations in both the system under study and in the measuring instrument, and second, the relative importance of force and displacement as variables under experimental control and subject to direct experimental measurement as a function of time.

 

Experimental research is the fundamental breeding ground for theory. In this regard, the cell analyzed from the single-molecule perspective becomes a unique laboratory for the study of the so-called Small Systems, namely, those that exchange energy in quantities similar to those of the thermal fluctuations. Both experiments and theory are thus reshaping how we envision Thermodynamics in the nanoscale.