Oxidative Phosphorylation
Oxidative Phosphorylation
- Occurs in the cristae of the mitochondria.
- Reactants:
- NADH
- FADH2
- Products
- H20
- Energy
- ATP
- Hydrogen atoms from NADH & FADH2 dissociate into electrons and protons, used in the synthesis of ATP by chemiosmosis, in ATP synthase at the end of the electron transport chain.
- Energy is released at each of the complexes in redox reactions.
- A proton gradient is created by the active transport of hydrogen ions (protons) into the intermembrane space, which diffuse out through ATP synthase via chemiosmosis, creating ATP.
- The electron transport chain cannot operate without oxygen, as oxygen is the electron acceptor at the end of the chain, forming water with protons. This cannot occur in anaerobic conditions.
Substrate Level Phosphorylation
- Production of ATP from ADP via the transfer of a phosphate group from a short lived, highly reactive intermediate such as creatine phosphate.
- This is different to oxidative phosphorylation as no electron transport change, chemiosmosis or ATP synthase is involved.