Anaerobic respiration

• What is the final electron acceptor in aerobic respiration?

  Oxygen
• What happens to the flow of electrons through the electron transport chain when oxygen concentration is low?

  The flow of electrons decreases
• What happens to coenzymes if electrons cannot flow through the electron transport chain?

  They cannot be regenerated
• From which processes do coenzymes NAD and FAD come?

  Glycolysis, link reaction, and Krebs cycle
• What is alcoholic fermentation in yeast cells?

  Anerobic respiration that converts pyruvate into ethanol
• What is the net ATP yield from glycolysis?

  2 ATP molecules
• What must happen to pyruvate during anaerobic respiration in yeast?

  It must be decarboxylated
• What enzyme catalyzes the conversion of pyruvate to ethanol?

  Pyruvate decarboxylase
• What is the role of NAD in glycolysis during anaerobic respiration?

  To accept hydrogens and regenerate NAD
• What happens to ethanol produced in yeast cells during fermentation?

  It becomes a toxic waste product
• What is the maximum ethanol concentration that yeast cells can tolerate before they die?

  15% ethanol
• What type of fermentation occurs in mammals?

  Lactate fermentation
• What is produced at the end of glycolysis in mammals?

  Pyruvate and 2 ATP molecules
• What enzyme catalyzes the conversion of pyruvate to lactate in mammals?

  Lactate dehydrogenase
• What is the purpose of regenerating NAD in lactate fermentation?

  To allow glycolysis to continue
• Where is lactate transported for detoxification in mammals?

  To the liver
• What process converts lactate back into glucose in the liver?

  Gluconeogenesis
• What is oxygen debt in mammals?

  The amount of oxygen required to convert lactate back into glucose
• How do aquatic mammals manage oxygen debt?

  By ventilating their system to replenish oxygen
• What is the role of the liver in detoxifying lactate?

  To convert lactate back into pyruvate and glucose
• Why is it important to maintain pH balance in the bloodstream?

  To prevent harmful effects on bodily functions
• What are the key steps in alcoholic fermentation in yeast cells?

  1. Glycolysis occurs, producing pyruvate and 2 ATP.
  2. Pyruvate is decarboxylated to produce ethanol and carbon dioxide.
  3. Ethanol accepts hydrogens from NAD, regenerating NAD.
  4. NAD allows glycolysis to continue, yielding more ATP.
• What are the key steps in lactate fermentation in mammals?

  1. Glycolysis occurs, producing pyruvate and 2 ATP.
  2. Pyruvate accepts hydrogens to become lactate.
  3. NAD is regenerated, allowing glycolysis to continue.
  4. Lactate is transported to the liver for detoxification.
• What are the differences between alcoholic fermentation and lactate fermentation?

  • Alcoholic fermentation produces ethanol; lactate fermentation produces lactate.
  • Alcoholic fermentation occurs in yeast; lactate fermentation occurs in mammals.
  • Both processes regenerate NAD to allow glycolysis to continue.
• What is the significance of the liver in anaerobic respiration in mammals?

  • Detoxifies lactate by converting it back to pyruvate and glucose.
  • Plays a role in maintaining energy balance during anaerobic conditions.
  • Helps repay oxygen debt after anaerobic respiration.
• What are the consequences of high lactate levels in mammals?

  • Lactate is toxic and can lead to muscle fatigue.
  • Requires conversion back to pyruvate and glucose in the liver.
  • Contributes to the buildup of oxygen debt.