Alcohol dehydrogenases in microbes function as tetramers . · They are zinc - containing enzymes that utilize glucose . Each glucose molecule is broken down in a 10 - step process called glycolysis . The product of glycolysis is two three - carbon sugars , called pyruvate , and ATP ( adenosine triphosphate ) . The two pyruvates are then converted into ethanol and carbon dioxide . The overall process of f mentation is to convert glucose sugar to alcohol and carbon dioxide gas . CHIN , → 2CH , CH , OH 2 co2 sugar alcohol carbon dioxide gas ( glucose ) ( ethyl alcohol or ethanol )