The citric acid cycle is a series of enzyme-catalysed chemical reactions, which take place in the matrix of the mitochondrion. The citric acid cycle is very importance in all living cells that use oxygen as part of cellular respiration. The components and reactions of the citric acid cycle were established by seminal work from Albert Szent-Györgyi and Hans Krebs. The citric acid cycle is also called the tricarboxylic acid cycle (TCA cycle), or the Krebs cycle. The Citric Acid Cycle is one of 3 stages of cellular respiration. The other stages are glycolysis and electron transport/oxidative phosphorylation.
The citric acid cycle is part of a metabolic pathway which participates in the chemical conversion of carbohydrates, fats and proteins into carbon dioxide and water to generate a form of usable energy. Other relevant reactions in the pathway include those in glycolysis and pyruvate oxidation before the citric acid cycle, and oxidative phosphorylation after it. In addition, it provides precursors for many compounds including some amino acids and is therefore functional even in cells performing fermentation.
Crystal-Clear Explanation of Citric Acid Cycle / Krebs Cycle (Animation)
The Krebs Cycle Video