Biotin is considered a coenzyme in the synthesis of:

Biotin, also referred to as vitamin B7, functions as a coenzyme in several important metabolic reactions in the body, particularly in the synthesis of fatty acids. It plays a crucial role in the carboxylation reactions, where it acts as a carrier of carbon dioxide. Specifically, biotin is involved in the activity of pyruvate carboxylase, an enzyme that converts pyruvate to oxaloacetate, and acetyl-CoA carboxylase, which is instrumental in the conversion of acetyl-CoA to malonyl-CoA, a key step in fatty acid biosynthesis.

The importance of biotin in fatty acid synthesis underscores its metabolic significance and the essential role it plays in lipid metabolism, thereby contributing to the overall energy balance and cellular function. The association of biotin with fatty acid synthesis exemplifies its role as a crucial coenzyme in processes of biosynthesis rather than in roles pertaining solely to protein, carbohydrate, or glycogen metabolism, although biotin does have relevance in other metabolic pathways as well.