Class: October 17th 2007

In our last class for this block we addressed how important are fluctuations in Biophysics and how useful information can be obtained for them. Thus, we first reviewed the Brownian motion and the Perrin's estimation of the Avogadro number (Perrin's Nobel Lecture can be found HERE: at the Monomolecular Films section you'll find the experiment I told you about soup bubbles). We also saw in class how equilibrium properties can be obtained from irreversible processes. In this regard, we introduced the concept of dissipation and the so-called Crooks fluctuation theorem that revealed that 2nd law is in fact violated for some trajectories. That violation is evident as the number of thermodynamics microstates is "small". Biophysics problems are therefore a good candidate to show those violations and in fact ARN pulling experiments (among others) have shown that is the case. In our next block we will deal even more with fluctuations and learn how can be properly described.
P.S. PLEASE REMEMBER ABOUT YOUR HOMEWORK!!!, also...please complete the questionnaires.