ABSTRACT
The tricarboxylic acid (TCA) cycle is one of the most fascinating and central cycles in biochemistry. It is also known as Kreb’s cycle, and the citric acid cycle. Muscle and brain, which require large amounts of energy, use the TCA cycle to produce high energy compounds such as adenosine triphosphate and nicotinamide adenine dinucleotide phosphate. On the other hand, the liver, which requires little energy, uses the TCA cycle to shuffle carbon skeletons to form amino acids and fats. Fat cells primarily use the TCA cycle to channel the carbon atoms of glucose to form fat. The first enzyme encountered catalyses the decarboxylation of pyruvate and is called either pyruvate decarboxylase or pyruvate dehydrogenase. The active enzyme is a complexed with the vitamin B1 derivative thiamine pyrophosphate, which is a common reactant in decarboxylation reactions.
