The development of synthetic catalysts is inspired by nature’s use of enzymes to achieve high reaction rates and 100% selectivity. These natural catalysts often contain inorganic nanoclusters at the active site, and it is an understanding of the activity and selectivity of these nanoclusters and their interaction with the surrounding protein, which can aid in the design of synthetic catalysts. Since natural and synthetic catalysts are composed of these nanoclusters, the fields of catalysis and nanoscience are inextricably linked.