Where does fatty acid synthesis occur?

Fatty acid synthesis occurs in the cytoplasm of the cell. This process is primarily carried out in liver and adipose tissue cells where the necessary enzymes, such as acetyl-CoA carboxylase and fatty acid synthase, are located. The cytoplasm provides the appropriate environment and necessary substrates for the synthesis of fatty acids from acetyl-CoA and malonyl-CoA through a series of enzymatic reactions.

During fatty acid synthesis, the intermediates are combined and elongated using NADPH as a reducing agent, which is produced in other metabolic pathways, such as the pentose phosphate pathway. The synthesis of fatty acids in the cytoplasm contrasts with the breakdown of fatty acids, which primarily occurs in the mitochondria through beta-oxidation.

Although the other organelles mentioned play vital roles in various cellular functions, they are not involved in the synthesis of fatty acids. The mitochondria are mainly responsible for ATP production and energy metabolism, the nucleus contains the genetic material and is involved in transcription and replication, and the Golgi apparatus functions in the modification and sorting of proteins and lipids, but not in the synthesis of fatty acids.