This isozyme preferentially catalyzes the conversion of primary unbranched alcohols to their corresponding aldehydes. Also shows activity toward secondary alcohols. a primary alcohol + NAD(+) = an aldehyde + H(+) + NADH a secondary alcohol + NAD(+) = a ketone + H(+) + NADH Binds 2 Zn(2+) ions per subunit. Homotetramer. PubMed:320000 sequence has several conflicting residues and reports microheterogeneities at additional postitions. Analysis of the sequence suggests that the sequenced protein was a mixture of at least 3 of the different isoforms of alcohol dehydrogenases found in yeast. Belongs to the zinc-containing alcohol dehydrogenase family.