Lipogenesis

Lipogenesis is the process by which acetyl-CoA is converted to fatty acids. The former is an intermediate compound in the metabolism of glucose and amino acids, and the latter are a major component of lipids, which are essential to all forms of life. Lipogenesis primarily occurs in the liver and adipose tissue.

Process

Lipogenesis begins with the carboxylation of acetyl-CoA to form malonyl-CoA, a reaction catalyzed by the enzyme acetyl-CoA carboxylase. Malonyl-CoA is then used as a substrate for the enzyme fatty acid synthase, which adds two-carbon units to the growing fatty acid chain. This process continues until a 16-carbon palmitic acid molecule is produced.

Regulation

The rate of lipogenesis is regulated by several factors, including the availability of substrates and the levels of certain hormones. For example, high levels of insulin and glucose can stimulate lipogenesis, while high levels of glucagon and epinephrine can inhibit it. Additionally, the rate of lipogenesis can be influenced by the dietary intake of carbohydrates and fats.

Clinical significance

Abnormalities in lipogenesis can lead to various health problems. For instance, overactive lipogenesis can contribute to obesity and metabolic syndrome, while underactive lipogenesis can lead to lipodystrophy and steatohepatitis. Furthermore, certain drugs, such as thiazolidinediones, can affect lipogenesis and are used in the treatment of type 2 diabetes and other metabolic disorders.

See also

• Lipolysis
• Fatty acid synthesis
• Fatty acid metabolism