What does flavin mean?
A flavin is a yellow, biologically important compound derived from riboflavin, better known as vitamin B2. In living cells, flavins such as flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) serve as tightly bound coenzymes, accepting and donating electrons during the oxidation-reduction reactions that underpin metabolism and energy production. The name reflects their striking color: the word derives from the Latin 'flavus', meaning yellow, and early chemists used 'flavin' for various yellow pigments found in plants and animals before biochemists narrowed the term to this specific family of molecules. Today the word appears almost exclusively in scientific writing, particularly studies of enzymes, mitochondria, and photobiology. Though rarely encountered outside laboratories, flavins are indispensable to nearly every organism on Earth, quietly enabling the chemical traffic of electrons that keeps cells alive.
nounA yellow organic pigment; in modern biochemistry, any of a group of yellow biologically active compounds derived from riboflavin (vitamin B2) that function as coenzymes in oxidation-reduction reactions.
- Any of a group of yellow biologically active compounds derived from riboflavin that act as coenzymes (as FAD and FMN) in redox reactions.
- A yellow plant or animal pigment (the older, broader chemical sense).
"The enzyme's activity depends on a tightly bound flavin that shuttles electrons during the reaction."
"Mitochondrial enzymes rely on flavin cofactors to transfer electrons along the respiratory chain."
"The researchers isolated a yellow flavin from the culture medium and identified it as riboflavin phosphate."
Standard pluralization; commonly used when discussing the class of compounds collectively.
"Both flavins were detected in the mitochondrial extract."
Every breath you take powers a tiny yellow engine inside your cells — and that engine runs on flavins.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of flavin
The word flavin comes ultimately from the Latin 'flavus', meaning yellow, adopted into scientific nomenclature in the nineteenth century to name the yellow pigments chemists were isolating from plants and animals. As biochemistry matured, the term was refined to designate the yellow compounds derived from riboflavin (vitamin B2) that function as electron-carrying coenzymes. The same Latin root gave rise to related scientific terms such as 'flavone', 'flavonoid', and 'flavoprotein', all of which preserve the connection to the color yellow.
How flavin is actually used
Flavin belongs almost entirely to scientific register — biochemistry, cell biology, and chemistry literature. In everyday English it is essentially unknown except through 'riboflavin' on nutrition labels. The original sense referring broadly to yellow pigments has largely given way to the specific biochemical meaning.
Easily confused with flavin
Riboflavin is vitamin B2 itself, whereas a flavin is one of the biologically active derivatives formed from it.
Flavonoids are plant metabolites that give fruits and flowers their colors, while flavins are vitamin-B2-derived coenzymes involved in cellular energy reactions.