Complex III, also known as the cytochrome bc1 complex, is a crucial component of the electron transport chain in cellular respiration. It is located in the inner mitochondrial membrane and plays a key role in transferring electrons from ubiquinol to cytochrome c, facilitating the production of ATP through oxidative phosphorylation. This complex consists of multiple protein subunits and contains important cofactors, including heme and iron-sulfur clusters. By pumping protons into the intermembrane space, Complex III helps create a proton gradient, which is essential for the synthesis of ATP by ATP synthase in the final steps of energy production.