Electron Transport Chain 10/21

Location of ETC: Inner Mitochondrial Membrane

• NADH and FADH2 molecules from earlier stages deliver high-energy electrons to the inner mitochondrial membrane proteins.

• Each membrane protein is more electronegative, facilitating the movement of electrons along the chain.

• Hydrogen ions (protons) are pumped into the intermembrane space using energy from the electrons, creating a concentration gradient.

• Oxygen serves as the final electron acceptor, combining with hydrogen to form water.

• This process creates a proton gradient, which is used to fuel ATP synthesis across the inner mitochondrial membrane.

• Hydrogen ions (protons) move from areas of high to low concentration through ATP synthase

• ATP synthase functions like a dam, harnessing the flow of H⁺ ions as it flows into the matrix which produces ATP.

• Oxidative Phosphorylation: The production of ATP is coupled with the movement of electrons through the electron transport chain (ETC) via ATP synthase.

• For each NADH, 3 ATP are produced.

• For each FADH₂, 2 ATP are produced.

• Each molecule delivers electrons at different complexes within the ETC.