TCA Cycle pptx (Biochemistry)

The TCA cycle, also known as the citric acid cycle or Krebs cycle, is a series of chemical reactions that occur in the mitochondria of eukaryotic cells and in the cytoplasm of prokaryotic cells. It is a central metabolic pathway involved in the aerobic respiration of carbohydrates, fats, and proteins.

The TCA cycle is an essential part of cellular respiration, as it plays a key role in the production of energy in the form of ATP. It also generates high-energy electron carriers, such as NADH and FADH2, which are used in the electron transport chain to produce more ATP.

The TCA cycle begins with the condensation of acetyl-CoA, derived from various fuel sources, with a four-carbon compound called oxaloacetate. This reaction forms a six-carbon molecule called citrate. Through a series of enzymatic reactions, citrate is gradually oxidized and rearranged, resulting in the regeneration of oxaloacetate.

During the cycle, several reactions take place, including the production of three molecules of NADH, one molecule of FADH2, and one molecule of ATP or GTP (guanosine triphosphate). These energy carriers are generated through oxidative decarboxylation and substrate-level phosphorylation.

The TCA cycle is a cyclic process because the initial molecule, oxaloacetate, is regenerated at the end of the cycle. Each turn of the cycle produces three molecules of NADH, one molecule of FADH2, and one molecule of ATP or GTP. These energy-rich molecules go on to participate in the electron transport chain, where they donate their electrons, leading to the production of additional ATP.

Overall, the TCA cycle serves as a central hub for the oxidation of fuel molecules and the generation of energy in the form of ATP. It is interconnected with other metabolic pathways and plays a vital role in maintaining cellular energy balance.