[Campbell Biology P.229] Which statement accurately differentiates alcohol fermentation from... | Practice Question

Which statement accurately differentiates alcohol fermentation from lactic acid fermentation based on the provided text and diagrams?

  • A: Alcohol fermentation produces more net ATP per glucose molecule than lactic acid fermentation.
  • B: Lactic acid fermentation releases carbon dioxide as a by-product, while alcohol fermentation does not.
  • C: Acetaldehyde is an intermediate in alcohol fermentation, but not in lactic acid fermentation.
  • D: Both processes require an electron transport chain for NAD+ regeneration.

Explanation

According to the 'In alcohol fermentation' section and Figure 9.16a, pyruvate is converted to acetaldehyde, which is then reduced to ethanol. Acetaldehyde is clearly an intermediate. In contrast, the 'During lactic acid fermentation' section and Figure 9.16b show pyruvate being directly reduced to lactate, with no acetaldehyde intermediate.