How does the efficiency of ATP production differ between the glycolytic and aerobic systems? (5 marks)
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- When glucose breaks down without oxygen, the glycolytic system only partly breaks down the fuel, resulting in lactic acid build-up.
- This happens because glucose cannot be fully broken down, leaving much energy still trapped in lactic acid.
- As lactic acid increases, it makes muscles more acidic which causes enzymes to work poorly and forces athletes to stop within 30-90 seconds.
- In contrast, when oxygen is available, the aerobic system completely breaks down glucose in the mitochondria, producing much more ATP per glucose molecule.
- This creates only carbon dioxide and water as waste products, which leave the body easily without causing tiredness.
- The aerobic system’s better efficiency allows energy production for hours, though at a slower rate than glycolysis.
- Therefore, athletes must choose: glycolytic speed for short bursts versus aerobic efficiency for longer efforts.
- Training improves both systems, but the basic efficiency difference stays the same because oxygen determines whether fuel breaks down completely or partially.
Show Worked Solution
Sample Answer
- When glucose breaks down without oxygen, the glycolytic system only partly breaks down the fuel, resulting in lactic acid build-up.
- This happens because glucose cannot be fully broken down, leaving much energy still trapped in lactic acid.
- As lactic acid increases, it makes muscles more acidic which causes enzymes to work poorly and forces athletes to stop within 30-90 seconds.
- In contrast, when oxygen is available, the aerobic system completely breaks down glucose in the mitochondria, producing much more ATP per glucose molecule.
- This creates only carbon dioxide and water as waste products, which leave the body easily without causing tiredness.
- The aerobic system’s better efficiency allows energy production for hours, though at a slower rate than glycolysis.
- Therefore, athletes must choose: glycolytic speed for short bursts versus aerobic efficiency for longer efforts.
- Training improves both systems, but the basic efficiency difference stays the same because oxygen determines whether fuel breaks down completely or partially.