Yeast convert pyruvate to ethanol and carbon dioxide, regenerating NAD+.
Pyruvate is decarboxylated to acetaldehyde (releasing CO2) and then reduced to ethanol by alcohol dehydrogenase. Yeast yields only 2 ATP per glucose. Used in brewing, wine and bread.
The CO2 produced makes bread rise and beer fizzy. Wine yeast tolerates high alcohol; other organisms die at lower levels.
Common mistake: yeast also respires aerobically when oxygen is available.
Yeast convert pyruvate to ethanol and carbon dioxide, regenerating NAD+.
Alcoholic Fermentation is one of the 53 topics in Metabolism & Bioenergetics. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Aerobic and Anaerobic Respiration, Link Reaction, Lactic Acid Fermentation.
Ethanol toxicity eventually stops yeast growth at about 12 to 15 percent.
Alcoholic Fermentation is a Beginner topic, so no earlier topic is required. Other Beginner topics in Metabolism & Bioenergetics that pair well with it include Metabolism, Anabolism and Catabolism, ATP.
The closest topics to Alcoholic Fermentation are Aerobic and Anaerobic Respiration, Link Reaction, Lactic Acid Fermentation, Glycolysis. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Alcoholic Fermentation. To practise the whole of Metabolism & Bioenergetics, use the Metabolism & Bioenergetics quiz.
Alcoholic Fermentation: Yeast convert pyruvate to ethanol and carbon dioxide, regenerating NAD+. Aerobic and Anaerobic Respiration: Aerobic uses oxygen for a large ATP yield; anaerobic occurs without oxygen with much less ATP. Read both side by side and note what each one explains.
Yeast also respires aerobically when oxygen is available.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Aerobic and Anaerobic Respiration and explain the difference aloud. Finally, take the Metabolism & Bioenergetics quiz and come back to this page for any question you miss.
Aerobic uses oxygen for a large ATP yield; anaerobic occurs without oxygen with much less ATP.
⚡ Metabolism & BioenergeticsPyruvate is oxidised to acetyl-CoA in the mitochondrial matrix, releasing carbon dioxide and forming NADH.
⚡ Metabolism & BioenergeticsPyruvate is converted to lactate when oxygen is lacking, regenerating NAD+ for glycolysis.
⚡ Metabolism & BioenergeticsA ten-step pathway in the cytoplasm that splits glucose into two pyruvate, yielding net 2 ATP and 2 NADH.
⚡ Metabolism & Bioenergetics