Fig. 1
A comparison of the time scales at which different X-ray sources can be applied, and the phenomena they might be used to observe. Biochemical processes span orders of magnitude in time, with faster process linked to electron transfer and photoisomerization, and slower events linked to conformational changes. Substrate diffusion into micron-sized crystals is faster than the average enzyme turnover time. The X-ray dose and time required to elicit a spectroscopic change and an X-ray diffraction pattern to high resolution at a modern synchrotron are illustrated with Deinococcus radiodurans phytochrome (Dr-BphP) and myoglobin (Mb)