The Blackburn Lab studies biological copper chemistry using biochemical, biophysical, and advanced spectroscopic techniques. Our research aims are two-pronged, which is reflected in this dissertation. First, we aim to elucidate the mechanism of mononuclear copper monooxygenases, specifically peptidylglycine α-hydroxylating monooxygenase (PHM) and dopamine β-monooxygenase (DβM), both of which catalyze the hydroxylation of high energy C-H bonds utilizing a pair of chemically distinct copper sites (referred to as the M- and H- center) separated by 11 Å. The second research aim is to develop an understanding of the molecular basis of cuprous transport and export in the bacterial periplasmic efflux pump CusCBA and its metallochaperone CusF, which are vital to the detoxification of copper and silver ions in the periplasm of Escherichia coli.