Here's a breakdown:

* Oxidative refers to the use of oxygen as the final electron acceptor in the electron transport chain.

* Phosphorylation refers to the addition of a phosphate group to a molecule, in this case, ADP (adenosine diphosphate) to form ATP (adenosine triphosphate).

Oxidative phosphorylation occurs in the mitochondria of eukaryotic cells and is the main source of ATP production in the body. It involves a series of steps:

1. Electron transport chain: Electrons are passed from molecule to molecule, releasing energy along the way.

2. Proton gradient: This energy is used to pump protons (H+) across the inner mitochondrial membrane, creating a concentration gradient.

3. ATP synthase: The protons flow back across the membrane through ATP synthase, a protein complex that uses the energy from the flow to add a phosphate group to ADP, forming ATP.

Let me know if you'd like more detail about any of these steps!