Figure 4.

Energy dissipation mediated by the uncoupling proteins. During respiration, protons are pumped by the respiratory chain complexes and a proton electrochemical potential gradient is generated. The energy of the proton gradient drives the synthesis of ATP by the F₀F₁-ATPase. UCPs catalyze a regulated re-entry of the protons into the matrix. The ADP/ATP carrier exports the newly synthesized ATP to the cytosol in exchange for ADP.