Virtually all knowledge of chemical and biochemical processes has been deduced from studies of a large number of molecules. The ability to look at individual molecules has given us new insights into biological processes. As an example, our polymer studies using DNA have fundamentally altered our thinking of polymer dynamics by showing that identical molecules placed under identical conditions take several distinct paths to a new equilibrium state.

We have been applying sensitive fluorescence microscopy to study the behavior of individual biomolecules. Using energy transfer between two dye molecules, a change in relative fluorescence from the two dyes can be used to measure the distance between two locations of a bio-macromolecule. Using this technique we are able to observe how the structure and the fluctuations in that structure determine the enzymatic reaction rate of a simple RNA enzyme (the hairpin ribozyme). We have also begun to study more complex interacting systems such as vesicle fusion that occurs in neuro transmission at the synapse. A brief account of our progress in vesicle fusion will also be given.