acetyl-CoA

Acetyl-CoA, or acetyl coenzyme A, is a molecule that is central to many metabolic pathways in living organisms. It is produced during the breakdown of carbohydrates, fats, and proteins, and is used as a building block for the synthesis of other important molecules. Acetyl-CoA is a small molecule that consists of a two-carbon acetyl group attached to a coenzyme A molecule. Coenzyme A is derived from the B vitamin pantothenic acid, and serves as a carrier of acetyl groups in many biochemical reactions. In cells, acetyl-CoA is involved in several important metabolic pathways. One of the key roles of acetyl-CoA is as a substrate for the citric acid cycle, also known as the Krebs cycle, which is a series of reactions that generate ATP, the energy currency of cells. In this cycle, acetyl-CoA is combined with oxaloacetate to form citrate, which is then converted into several intermediate molecules, ultimately producing ATP. Acetyl-CoA is also used as a building block for the synthesis of fatty acids, cholesterol, and other important lipids. It is also involved in the production of several neurotransmitters, such as acetylcholine, and is a precursor for the synthesis of several amino acids. In addition to its metabolic functions, acetyl-CoA also plays a regulatory role in the cell. It can act as a substrate for acetylation reactions, which can modify the activity of certain enzymes and other proteins. Acetylation can also affect the function of histones, which are proteins that help to package DNA in the nucleus, and can therefore influence gene expression.