Final answer:
Alcohol dehydrogenase generates NAD+ during fermentation, also leading to the production of ethanol; this enzyme is essential in producing alcoholic beverages and bread.
Step-by-step explanation:
The enzyme alcohol dehydrogenase generates NAD+ during fermentation. The alcohol fermentation process is a two-step reaction, with the first step involving the enzyme pyruvate decarboxylase that removes a carboxyl group from pyruvic acid, producing acetaldehyde and releasing carbon dioxide gas (CO2). In the second step, alcohol dehydrogenase catalyzes the reaction where NADH transfers an electron to acetaldehyde, thereby converting it to ethanol and regenerating NAD+. This biochemical process is a form of anaerobic respiration used by yeast and some bacteria, and it is critical for the production of alcoholic beverages and bread products.