What does dehydrogenase mean?
A dehydrogenase is any of a broad class of enzymes that catalyzes the removal of hydrogen atoms from a molecule, effectively oxidizing that molecule. The stripped hydrogen is not simply released; instead, the enzyme hands it off to a carrier such as NAD+, NADP+, or FAD, which then shuttles the energy onward through the cell's metabolic pathways. Because this reaction underpins processes as fundamental as respiration, fermentation, and detoxification, dehydrogenases are among the most studied enzymes in biochemistry. They are always referred to by their substrate — lactate dehydrogenase, alcohol dehydrogenase, malate dehydrogenase — so the bare term denotes a family rather than a single substance. Clinically, blood levels of certain dehydrogenases serve as important diagnostic markers: elevated lactate dehydrogenase, for instance, can indicate tissue damage ranging from a heart attack to hemolysis. Though purely scientific in register, the word repays attention, since these enzymes quietly perform some of the chemistry on which every living cell depends.
nounAn enzyme that catalyzes the removal of hydrogen atoms from a substrate, thereby oxidizing it, typically transferring the hydrogen to an electron acceptor such as NAD+ or FAD.
- Any of various enzymes that catalyze the oxidation of a substrate by removing hydrogen atoms and transferring them to an acceptor molecule such as NAD+, NADP+, or FAD.
"Lactate dehydrogenase converts lactate to pyruvate during anaerobic metabolism."
"The blood test measured elevated levels of lactate dehydrogenase, suggesting tissue damage."
"Alcohol dehydrogenase in the liver converts ethanol into acetaldehyde."
Regular plural, used when referring to multiple enzymes of this class or multiple instances across different organisms or tissues.
"Dehydrogenases play a central role in cellular respiration and energy production."
Every sip of alcohol you've ever taken was broken down by alcohol dehydrogenase — the same enzyme your body has used for millions of years, long before humans learned to ferment anything.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of dehydrogenase
The word combines three elements of modern scientific coinage: the prefix 'de-', Greek 'hydor' (water) via 'hydrogen' ('water-forming'), and the '-ase' ending introduced around the turn of the twentieth century by the French chemist Émile Duclaux to standardize enzyme names. The name thus literally describes the enzyme's action — taking hydrogen away from a substrate. It arose alongside the wider biochemical nomenclature of the late nineteenth and early twentieth centuries and shares its roots with words such as 'hydrogen', 'hydrogenate', and 'dehydrogenate'.
Related word forms
How dehydrogenase is actually used
Strictly technical vocabulary used almost exclusively in biochemistry, medicine, and related laboratory sciences; it does not appear in everyday conversation. It functions as a count noun and is nearly always named in combination with its specific substrate (e.g., lactate, alcohol, glucose-6-phosphate), since 'dehydrogenase' alone refers to a whole class of enzymes rather than one specific protein.
Easily confused with dehydrogenase
A dehydratase removes water (not hydrogen) from a substrate, whereas a dehydrogenase removes hydrogen atoms and transfers them to a coenzyme or other acceptor.
An oxidase transfers electrons directly to molecular oxygen, while a dehydrogenase usually passes hydrogen to NAD+, FAD, or another acceptor rather than to oxygen itself.