Proteins in your body perform their special functions because that have shapes that are folded into convoluted structures. The folded structure has the correct active sites in the correct conformations to allow enzymes to do their job. Therefore, folded proteins are necessary for life.
The process of protein folding is a dynamic process that can occur on wide timescales ranging from picoseconds to milliseconds. Such a wide dynamic range requires specialized tools to track the folding dynamics. Lasers and optics provide one such method for tracking these dynamics.
Recent work on cytochrome has made it possible to use light to trigger protein folding by optically inducing electron transfer.