This tutorial review discusses the immobilization of alkyne-terminated cytochrome c oxidase models on azide-functionalized self-assembled monolayers (SAM) coated gold electrodes that was made possible by click chemistry. The rate of electron delivery from the electrode to the model could be tuned by changing the nature of the SAM. Biologically relevant electron transfer rates (2-4 s(-1)) were obtained on slow SAMs allowing the model to turn over catalytically under steady-state conditions. Hence, click chemistry was a crucial tool to demonstrate, through electrocatalytic studies: (1) the role played by several features present in the distal side of the model, such as the Cu(B)-Tyr244 pair, the distal pocket, and the stabilizing role of a distal water cluster; (2) the reversible inhibition of O(2) reduction by H(2)S.