The cover picture shows, in the background, the X-ray crystal structure of sperm whale muscle carbonmonexy myoglobin at 1.15 A resolution (PDB code 1BZR) as determined by Kachalos, Popov, and Bartunik (Scrence 1999, 284, 473-476) The artwork was generated with Yasar 8.8.12 (E. Krieger et al, Proteins 2001, 47, 39-402) and POV Ray 3.6.1. Superimposed on this is a trace of UV/Vis spectra from the Q-band region of myoglobin observed upon binding of increasing amounts of carbonmonoxide liberated from a CORM (CO releasing molecule, J. Niesel, U. Schatzschneider stal Cham Commun 2008, 1798-1800). A variation of this experiment is described in Chapter 1.