Alcohol dehydrogenase. Oxidizes primary as well as secondary alcohols. Ethanol is a very poor substrate. a primary alcohol + NAD(+) = an aldehyde + H(+) + NADH a secondary alcohol + NAD(+) = a ketone + H(+) + NADH butan-1-ol + NAD(+) = butanal + H(+) + NADH 1-propanol + NAD(+) = H(+) + NADH + propanal Binds 2 Zn(2+) ions per subunit. Dimer of identical or heterodimer of closely related subunits alpha, beta, or gamma that are encoded by genes ADH1A, ADH1B, and ADH1C, respectively. Belongs to the zinc-containing alcohol dehydrogenase family.