Acetyl-CoA carboxylase (ACC) is a complex multifunctional enzyme system. ACC is a biotin-containing enzyme which catalyzes the carboxylation of acetyl-CoA to malonyl-CoA, the rate-limiting step in fatty acid synthesis. There are two ACC forms, alpha and beta, encoded by two different genes. Acetyl-CoA Carboxylase 1 also known as ACC1, ACCα is predominantly expressed in lipogenic tissues and regulated by phosphorylation and dephosphorylation of specific serine residues, as well as by allosteric interactions with metabolites such as citrate and palmitoyl-CoA. These regulatory mechanisms ensure fatty acid synthesis is appropriately modulated in response to cellular energy demands and nutritional status. Located on human chromosome 17, ACCα plays a significant role in metabolic pathways.