Alcohol dehydrogenases

A group of enzymes catalysing the oxidation of alcohols to aldehydes or ketones — EC 1.1.1.1 in the classic listing — with concomitant reduction of NAD+ to NADH. In humans they perform the first step of ethanol metabolism, converting drink to acetaldehyde in the liver; genetic variants explain much of the difference in alcohol tolerance between populations. Fermenting microbes wield their own versions to manage redox balance. In food analysis they are working tools: enzymatic alcohol assays built on alcohol dehydrogenase give rapid, specific measurements of ethanol in beverages.