Answer:
The electron transport chain is a series of protein complexes and electron carriers that are located in the inner membrane of the mitochondria. These complexes and carriers are involved in the transfer of electrons from NADH and FADH2, produced during glycolysis and the Krebs cycle, to oxygen, the final electron acceptor. The energy released from this transfer is used to pump protons across the inner mitochondrial membrane, generating a proton gradient that drives the production of ATP.
The key events of the electron transport chain include the following:
The transfer of electrons from NADH to complex I, also known as NADH-ubiquinone oxidoreductase, by the enzyme NADH dehydrogenase. This complex consists of several protein subunits and a non-protein electron carrier called ubiquinone.
The transfer of electrons from complex I to complex II, also known as succinate-ubiquinone oxidoreductase or succinate dehydrogenase, by the enzyme ubiquinone. Complex II consists of several protein subunits and a non-protein electron carrier called ubiquinone.
The transfer of electrons from complex II to complex III, also known as ubiquinone-cytochrome c oxidoreductase or cytochrome bc1 complex, by the enzyme cytochrome b. Complex III consists of several protein subunits and two non-protein electron carriers called cytochromes c1 and c.
The transfer of electrons from complex III to complex IV, also known as cytochrome c oxidase or cytochrome aa3, by the enzyme cytochrome c. Complex IV consists of several protein subunits and two non-protein electron carriers called cytochromes a and a3.
The transfer of electrons from complex IV to oxygen by the enzyme cytochrome a3. Oxygen is the final electron acceptor in the electron transport chain.
As the electrons are transferred through the complexes of the electron transport chain, energy is released and used to pump protons across the inner mitochondrial membrane. This creates a proton gradient that drives the synthesis of ATP by the enzyme ATP synthase. The end products of the electron transport chain are water and ATP.
Step-by-step explanation: