Figure 2: Krebs (TCA or citric acid) cycle generating 2GTP (equal to 2ATP) and collecting eight high-energy electrons from intermediate metabolites via oxidation and transport. These energy electrons are 6 NADH and 2 FADH2 as a carrier to the electron transport chain (ETC). Acetyl CoA + 3NAD+ FAD + GDP + Pi. + 2H₂O → 2CO₂ + CoA + 3NADH + FADH₂ +GTP + 2H⁺.