Electron Transport Chain

• The electron transport chain occurs on and in the mitochondrial membrane called the cristae
• 1. The ETC is composed of multiple hydrogen carriers at varying energy levels 
• 2. As the hydrogen and their electrons pass through, the carrier molecules release their energy which is sufficient enough to convert ADP+Pi to ATP
• 3. The hydrogen carriers become reduced as hydrogen passes through, these carriers are then oxidised as the hydrogen or electrons are removed, which is known as a redox reaction
• 4. The NADH2 passes the hydrogen to flavoprotein, making reduced flavoprotein. The energy gap is so large that enough energy is produced to convert ADP + Pi to ATP
• 5. The reduced flavoprotein passes hydrogen atoms to coenzyme Q
• 6. At this point, cytochromes are involved which can only carry electrons. As a result, the hydrogen atoms dissociate to form hydrogen ions and electrons and the hydrogen ions diffuse to the end of the chain
• 7. Electrons are passed through the cytochromes, in which 2 ATP molecules are produced
• 8. The final hydrogen acceptor is oxygen, oxygen combines with the hydrogen ions and the electrons to produce water and this reaction is catalysed by the enzyme cytochrome oxidase.
• 9. The generation of ATP in the ETC occurs by oxidative phosphorylation 
• 10. One glucose molecule produces up to 38 ATP by oxida phosphorylation, 19 per pyruvate
• 11. oxygen is required for the ETC as without it the carriers would remain reduced