Here's how it works:
* Glucose is oxidized: During cellular respiration, glucose is broken down through a series of redox reactions. This process involves the removal of electrons from glucose, which are picked up by electron carriers like NAD+ and FAD.
* NAD+ and FAD are reduced: When NAD+ gains an electron, it becomes NADH. Similarly, FAD gains two electrons to become FADH2. These reduced forms of the electron carriers now hold the energy originally stored in glucose.
* Energy transfer: NADH and FADH2 then carry these high-energy electrons to the electron transport chain, where they are used to generate a proton gradient. This gradient is then used by ATP synthase to produce ATP, the primary energy currency of cells.
In essence, NADH and FADH2 act as temporary energy storage molecules that shuttle electrons and their associated energy from glucose to the electron transport chain, ultimately driving ATP production.
