Here's a breakdown:
* NADH and FADH2 are electron carriers: They are reduced forms of NAD+ and FAD, respectively. They gain electrons during the breakdown of glucose (glycolysis and the Krebs cycle) and then deliver these electrons to the electron transport chain.
* Electron transport chain: This chain of protein complexes embedded in the mitochondrial membrane uses the energy from the electrons carried by NADH and FADH2 to pump protons across the membrane, creating a proton gradient.
* ATP production: This gradient drives the production of ATP, the main energy currency of cells, through oxidative phosphorylation.
In essence, NADH and FADH2 are vital for the final stages of cellular respiration, ensuring the efficient production of ATP from the breakdown of glucose.
