What is the Difference Between FAD and FMN?

Flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) are biomolecules that play essential roles in various biological processes. The key difference between FAD and FMN lies in their structure and the number of nucleotide components:

• FAD (Flavin Adenine Dinucleotide) contains two nucleotide components and is involved in several enzymatic reactions in metabolism. It is a redox-active coenzyme associated with various proteins, including components of the succinate dehydrogenase complex, α-ketoglutarate dehydrogenase, and the pyruvate dehydrogenase complex.
• FMN (Flavin Mononucleotide) contains only one nucleotide component. It is mainly useful as a food additive in milk products, sweets, and baby food for orange-red coloration.

In addition to their roles in metabolism, flavoproteins containing FAD or FMN as prosthetic groups catalyze many one- and two-electron oxidation/reduction reactions critical to various cellular processes. While FAD is present in complex II, ETF, and α-glycerophosphate dehydrogenase, FMN is a component of complex I.

Comparative Table: FAD vs FMN

FAD (Flavin Adenine Dinucleotide) and FMN (Flavin Mononucleotide) are both biomolecules found in organisms and serve as coenzymes for riboflavin. The key difference between FAD and FMN is that the FAD molecule contains two nucleotide components, whereas FMN contains only one nucleotide component. Here is a table comparing the two:

Both FAD and FMN play crucial roles in different cellular processes, such as redox reactions, DNA repair, chromatin remodeling, protein folding, detoxification, neural development, and apoptosis.