What is TCA cycle.write its role …

The TCA cycle is a central pathway into which many metabolites feed. It consists of a number of reactions which generate NADH and FADH₂ which can in turn be used by the oxidative phosphorylation pathway to generate ATP. The TCA cycle occurs in the matrix of the mitochondria. The citric acid cycle is a series of reactions that produces two carbon dioxide molecules, one GTP/ATP, and reduced forms of NADH and FADH2. The regulation of the rate of oxidative phosphorylation by the ADP level is called respiratory control or acceptor control. The level of ADP likewise affects the rate of the citric acid cycle because of its need for NAD+ and FAD. The physiological significance of this regulatory mechanism is evident. The major significance of the citric acid cycle is to act as the final common pathway for the oxidation of carbohydrates, lipids and proteins, since glucose, fatty acids and many amino acids are all metabolised to acetyl CoA.