1. ATP (Adenosine Triphosphate): The Krebs cycle directly produces a small amount of ATP (one molecule per cycle) through substrate-level phosphorylation. This is a relatively minor energy yield compared to the electron transport chain.
2. Reduced electron carriers (NADH and FADH2): The Krebs cycle generates a significant amount of reduced electron carriers, specifically NADH and FADH2. These molecules carry high-energy electrons that are subsequently used in the electron transport chain to generate a large amount of ATP (the main energy currency of cells).
So, while the Krebs cycle directly produces a small amount of ATP, its primary role is to generate reduced electron carriers that fuel the subsequent ATP production in the electron transport chain.
