Fatty acid synthesis

Fatty acid synthesis is the biological process by which fatty acids are produced from acetyl-CoA, malonyl-CoA, and NADPH. This process takes place in the cytoplasm of cells and is vital for the production of lipids (fats), which are essential components of all cells.

Process

Fatty acid synthesis begins with the carboxylation of acetyl-CoA to malonyl-CoA, a reaction catalyzed by the enzyme acetyl-CoA carboxylase. This is the committed step of fatty acid synthesis because it is the point at which the cell commits to using the acetyl-CoA molecule for lipid synthesis.

The malonyl-CoA is then transferred to a protein called fatty acid synthase, which carries out the remaining steps of the process. These steps include a series of reductions and condensations that result in the addition of two carbon atoms to the growing fatty acid chain for each cycle of the process.

The final product of fatty acid synthesis is usually a 16-carbon fatty acid called palmitic acid. However, the process can be modified to produce other types of fatty acids, such as stearic acid and oleic acid, by the action of additional enzymes.

Regulation

Fatty acid synthesis is tightly regulated by a variety of mechanisms to ensure that it occurs only when necessary. For example, the enzyme acetyl-CoA carboxylase is regulated by both allosteric control and covalent modification. In addition, the availability of substrates and the energy status of the cell also influence the rate of fatty acid synthesis.

Clinical significance

Abnormalities in fatty acid synthesis can lead to a variety of health problems. For example, deficiencies in the enzymes involved in the process can lead to fatty acid synthesis disorders, which can cause a variety of symptoms ranging from mild to severe. In addition, overactive fatty acid synthesis is associated with obesity and type 2 diabetes, as it can lead to an excess of stored fat in the body.

See also

• Lipid metabolism
• Fatty acid degradation
• Fatty acid elongation