respiration - anaerobic

Question 1

Explain how energy is released by respiration in the absence of oxygen

Answer 1

In the absence of oxygen FAD and NAD will be reduced but unable transfer their hydrogen atoms in the electron transfer chain. This results in NAD and FAD being unavailable for further reduction during krebs cycle. Only glycolysis can occur, this happens due to hydrogen being removed from reduced NAD by the pyruvate that has been produced.

Question 2

Explain how ethanol is produced by anaerobic respiration

Answer 2

Some bacteria, fungi and plants produce ethanol during anaerobic respiration (fermentation). The pyruvate from glycolysis loses a carbon dioxide molecule and accepts hydrogen from reduced NAD to form ethanol.

Question 3

Explain how lactate is produced by anaerobic respiration

Answer 3

Animals in short supply of oxygen produce lactate (also known as lactic acid). Pyruvate from glycolysis removes hydrogen from reduced NAD to form lactate.