Where does oxidative phosphorylation occur in a cell?

Oxidative phosphorylation occurs in the inner mitochondrial membrane, where the electron transport chain and ATP synthase are located. This process is crucial for cellular respiration as it generates the majority of ATP through the coupling of electron transfer to the phosphorylation of ADP.

During oxidative phosphorylation, electrons are transferred through a series of protein complexes in the inner mitochondrial membrane, ultimately reducing oxygen to form water. As electrons pass through these complexes, protons are pumped from the mitochondrial matrix into the intermembrane space, creating a proton gradient. This electrochemical gradient drives protons back into the matrix through ATP synthase, facilitating the conversion of ADP and inorganic phosphate into ATP.

The other options are not correct because oxidative phosphorylation does not occur in the cytoplasm, outer mitochondrial membrane, or nucleus. The cytoplasm is where glycolysis takes place, the outer mitochondrial membrane does not house the necessary components for oxidative phosphorylation, and the nucleus is where genetic material resides, not the site of ATP production through this specific mechanism.