Energy yield comparison: aerobic catabolism vs. fermentation Relative to glucose fermentation, how much ATP does complete aerobic catabolism of glucose synthesize in typical cells?

Introduction / Context:
Cells can harvest energy from glucose via fermentation or aerobic respiration. Fermentation yields ATP only through substrate-level phosphorylation, whereas respiration uses both substrate-level and oxidative phosphorylation. Comparing yields is basic to microbial physiology and bioenergetics.

Given Data / Assumptions:

• Fermentation of glucose typically yields 2 ATP per glucose.
• Aerobic respiration in bacteria can yield up to ~38 ATP per glucose (organism and conditions dependent); eukaryotes commonly yield ~30–32 ATP.
• We are asked for an order-of-magnitude comparison, not an exact number.

Concept / Approach:

Because aerobic respiration captures electrons into an electron transport chain and uses oxygen as the terminal electron acceptor, the proton motive force drives ATP synthase to generate far more ATP than fermentation alone. Even conservative yields far exceed ten times the fermentative yield.

Step-by-Step Solution:

Verification / Alternative check:

Even with organism variability and P/O ratio differences, respiration’s yield is consistently an order of magnitude higher than fermentation.

Why Other Options Are Wrong:

• Slightly less/About the same/Twice: All underestimate respiratory ATP gains.
• Exactly five times: Also too low; respiration greatly exceeds this ratio.

Common Pitfalls:

• Treating the textbook 38 ATP as exact; actual yields vary, but still greatly surpass fermentation.

Final Answer:

More than 10 times as much