What is Acetyl-CoA?

Acetyl-CoA, or activated acetate, is an important molecule in the metabolism processes of the human body. Composed of two carbon atoms, this coenzyme is the metabolic product of the oxidation of several amino acids, pyruvate and fatty acids. It is then broken down and used by the body for energy production. This process is called the citric acid cycle, or Krebs cycle. As vital as it is in the metabolic process, it is possible to have too much, causing undesired health issues, such as high cholesterol.

The citric acid cycle is a metabolic process by which eight enzymes are used for the production of energy in aerobic oxidation. The cycle begins in mitochondria, where acetyl-CoA is oxidized. Through further metabolism, the body is then able to create adenosine triphosphate (ATP), the type of energy used within the cells of the body for a wide array of biological processes. The activated acetate enters the citric acid cycle at a specific juncture, at which time it used combined with two carbon atoms, thus creating citrate.

The acetyl-CoA that is used in the Krebs cycle comes from two main sources. The first source of the molecule is pyruvate, an organic acid that can be converted into carbohydrates, fatty acids or energy. In the case of the the citric acid cycle, it supplies energy to cells. Pyruvate is typically derived from glycolysis, which is the process by which the body breaks down sugars and other carbohydrates. The metabolism of fatty acids is another common source of activated acetate.

Though necessary for proper metabolism, it is possible to have overly high levels of this molecule in the body. Along with the more commonly known negative consequences of sugar consumption, high levels of sucrose in the diet can also have an adverse effect on the metabolic process, including on this coenzyme. Excessive levels can cause negative side effects. When the body has more available than is needed for the Krebs cycle, it sends the excess to be dealt with by the pancreas through the use of insulin. This excess is then either used in the synthesis of body fat or used in the creation of HMG-CoA, which triggers the production of cholesterol, causing high cholesterol levels in the blood.