For example, formaldehyde dehydrogenase has absolute specificity since it catalyzes only the reaction for formaldehyde. Acetylcholinesterase has absolute specificity for biotransforming the neurotransmitting chemical, acetylcholine. Alcohol dehydrogenase has group specificity since it can biotransform several different alcohols, including methanol and ethanol. N-oxidation can catalyze a reaction of a nitrogen bond, replacing the nitrogen with oxygen.
The names assigned to enzymes may seem confusing at first. However, except for some of the originally studied enzymes (such as pepsin and trypsin), a convention has been adopted to name enzymes. Enzyme names end in "ase" and usually combine the substrate acted on and the type of reaction catalyzed. For example, alcohol dehydrogenase is an enzyme that biotransforms alcohols by the removal of a hydrogen. The result is a completely different chemical, an aldehyde or ketone.
The biotransformation of ethyl alcohol to acetaldehyde is depicted below: