Illustrated Glossary of Organic Chemistry

Alcohol dehydrogenase: An enzyme that oxidizes an alcohol to an aldehyde or ketone, by transferring a hydride ion and a proton from the alcohol to a coenzyme such as NAD+. In the reverse reaction, alcohol dehydrogenase uses NADH to reduce an aldehyde or ketone to an alcohol.

Ethanol metabolism in yeast or the human liver begins with oxidation by alcohol dehydrogenase and NAD+ to give acetaldehyde and NADH.