The effects of metals on oxdative phosphorylation, ATPase and electron transport were examined. Cadmium accelerated state 4 respiration and increased latent ATPase activity, indicating that cadmium is an uncoupler of the energy transport reaction. Cadmium did not inhibit site 1, 2 or 3 of the electron transport chain. Copper inhibited state 3 respiration, accelerated state 4 respiration, increased latent ATPase activity and decreased stimulated ATPase activity, indicating that copper is an uncoupler and effects the energy tranport reaction. Copper did not inhibit site 1, 2 or 3 of the electron transport chain. Zinc inhibited state 3 and state 4 respiration, increased latent ATPase activity, decreased stimulated ATPase activity slightly, and inhibited sites 1 and 2 of the electron tranport chain. One pair of the 3 metals had additive effects on state 3 and 4 respiratory activity and on stimulated and latent ATPase activity. A competitive reaction between copper and zinc was observed in the effects on sites 1 and 2 of the electron transport chain.
Electron Transport System