Complex IV, also known as cytochrome c oxidase, is a crucial enzyme in the electron transport chain, which is part of cellular respiration. It is located in the inner mitochondrial membrane and plays a key role in the production of adenosine triphosphate (ATP), the energy currency of the cell. Complex IV catalyzes the transfer of electrons from cytochrome c to molecular oxygen, facilitating the reduction of oxygen to water. This process is essential for maintaining the proton gradient across the mitochondrial membrane, which drives ATP synthesis. By pumping protons into the intermembrane space, Complex IV helps create the conditions necessary for ATP synthase to generate ATP. Dysfunction in Complex IV can lead to various metabolic disorders and is associated with certain diseases.