What must be regenerated from NADH and FADH2 for the TCA cycle to continue?

Step-by-step solution

During the conversion of succinyl-CoA to succinic acid a molecule of GTP is synthesised. This is a substrate level phosphorylation. In a coupled reaction GTP is converted to GDP with the simultaneous synthesis of ATP from ADP. Also there are three points in the cycle where NAD+ is reduced to NADH + H+ and one point where FAD+ is reduced to FADH2 . The continued oxidation of acetyl CoA via the TCA cycle requires the continued replenishment of oxaloacetic acid, the first member of the cycle. In addition it also requi