The citric (KREBS) acid cycle
The citric acid cycle (Krebs cycle) metabolizes AcetylCoA mainly obtained from pyruvic acid by glycolysis.
3 α -Cetoglutarate
4 Succinyl CoA
For glycolysis see → here
For the passage from pyruvate to acetylCoA see → here
For details on the role of NAD+ see → here
For details on the role of the FAD see → here