Topic 3 Cellular Respiration: Anaerobic Respiration (cytosol)

Question 1

• Includes glycolysis and fermentation

- Regenerated NAD+ via O2, which is required for continuation of glycolysis.

Answer 1

Anaerobic Respiration (cytosol)

Question 2

• In plants, fungi, and bacteria
• Pyruvate -> acetaldehyde + CO2, then acetaldehyde -> ethanol (and NADH -> NAD+)
• Acetaldehyde is the final electron acceptor, forming ethanol as the final product. O2 is the final electron acceptor of cellular respiration, forming H2O.

Answer 2

Alcohol Fermentation

Question 3

• Occurs in human muscle cells
• Pyruvate -> lactate (and NADH -> NAD+)
• Lactate is transported to liver for conversion back to glucose

Answer 3

Lactic Acid Fermentation

Question 4

• Use oxygen when present, but switches to fermentation/anaerobic respiration if isn’t

Answer 4

Facultative Anaerobes

Question 5

• Acts as key juncture in catabolism: both fermentation and cellular respiration use glycolysis to produce two pyruvate molecules. At this point, the pathway splits. For cells capable of aerobic cellular respiration or fermentation, the pathway is usually selected based on the presence or absence of oxygen.

Answer 5

Pyruvate