Here's why:
* Glycolysis (the first stage) produces a small amount of ATP (2 molecules) and NADH.
* The Krebs Cycle (second stage) produces some ATP (2 molecules), but its main contribution is generating NADH and FADH2, electron carriers.
* Oxidative Phosphorylation (third stage) is where the majority of ATP is produced. This process harnesses the energy stored in the electron carriers (NADH and FADH2) from previous stages. It uses a series of protein complexes in the mitochondrial membrane to create a proton gradient, which is then used to power ATP synthase, producing a large number of ATP molecules.
Therefore, oxidative phosphorylation is the most energy-yielding stage of respiration.
