The Krebs cycle also known as the citric acid cycle, tricarboxylic acid cycle or TCA cycle was discovered by Hans Adolf Krebs who discovered this series of chemical reactions that are essential to proper bodily function.
Its purpose is to produce 2 molecules for the respiratory chain. These are NADH and FADH2 respectively which are produced by the degradation of the simple sugar glucose to carbon dioxide and water. This is actually the 3rd part in a 4 step process and is commonly referred to as carbohydrate catabolism. The others are in order: glycolysis (1rst), oxidative decarboxylation(2nd) and oxidative phosphorylation.
The citric acid cycle occurs in the mitochondrion where the enzymes are located. Here glucose is first converted to pyruvic acid through glycolysis. Then the first step in the citric acid cycle takes place. A molecule of glucose is broken down 2x since 2 molecules of pyruvate are released.
The actual name “citric acid cycle” gets its moniker from the fact that citric acid is one of the first products that arise from the number of conversions that occur at this time.