<P> In humans , ADH exists in multiple forms as a dimer and is encoded by at least seven different genes . There are five classes ( I-V ) of alcohol dehydrogenase , but the hepatic form that is used primarily in humans is class 1 . Class 1 consists of α , β , and γ subunits that are encoded by the genes ADH1A , ADH1B , and ADH1C . The enzyme is present at high levels in the liver and the lining of the stomach . It catalyzes the oxidation of ethanol to acetaldehyde ( ethanal ) : </P>
where is alcohol dehydrogenase found in the body
present at high levels in the liver and the lining of the stomach