The tricarboxylic acid (TCA) cycle is also known as the Krebs or citric acid cycle which is the main source of energy for cells and it is an important part of aerobic respiration.
In this cycle the chemical energy of acetyl coenzyme A (acetyl CoA) is reduced into the into the power of nicotinamide adenine dinucleotide (NADH).
The TCA cycle is the part of larger glucose metabolism whereas glucose is oxidized to form pyruvate, which is then oxidized and enters into the TCA cycle as acetyl-CoA.
Hans Krebs discovered the TCA cycle, therefore, it is also known as the Krebs Cycle.