INTRODUCTION

The citric acid cycle, Krebs cycle, or tricarboxylic acid cycle is the pathway that occurs in mitochondria that oxidises acetyl-CoA and reduces the coenzymes NADH⁺ and FADH₂ reoxidised through the electron transport chain. The third phase of metabolism is the citric acid cycle. The carbohydrate, lipid and protein finally meet in this pathway, because glucose, fatty acids and most amino acids are catabolised to acetyl-CoA or any of the intermediates of this pathway.