Anaerobic Respiration and Fermentation

Question 1

Aerobic Respiration

Answer 1

• Uses O2

- Generates 36 ATP (eukaryotes) and 38 ATP (prokaryotes)

Question 2

Anaerobic Respiration

Answer 2

• Uses NO3-, SO4^2-, CO3^2-, or other substance

- Generates fewer ATP than aerobic

Question 3

Prokaryotes can support respiration without O2 by…

Answer 3

…using alternate oxidases (e.g. nitrate reductase)

Question 4

Denitrification in Paracoccus

Answer 4

• Uses appropriate reductases in ETC

- Nitrate to Nitrite to Nitric Oxide to Nitrous Oxide and finally to Dinitrogen

Question 5

Fermentation

Answer 5

• Organic metabolite (pyruvate or derivative) is used as final electron acceptor
• Mechanism for regenerating NAD+ without O2

Question 6

Reactions of Fermentation

Answer 6

After glycolysis…

1. Pyruvate converted to lactate (using 2 NADH)
2. Pyruvate converted to acetaldehyde and CO2; then converted to ethanol (using 2 NADH)

Question 7

Types of Lactic Acid Fermentation

Answer 7

• Homolactic: Only lactic acid

- Heterolactic: Lactic acid and other compounds