Higher Tier: lactic acid and recovery
הוצג| English | משמעות |
|---|---|
| lactic acid/ˈlæktɪk ˈæsɪd/ | חומצה לקטית |
| oxygen debt/ˈɒksɪdʒn det/ | חוב חמצן |
What would explain this observation?
- Higher Tier: Stopping an activity does not immediately return oxygen demand to its resting level. Recovery includes handling substances accumulated during anaerobic respiration.
Build the model
- When oxygen supply cannot meet vigorous muscle demand, incomplete glucose oxidation produces lactic acid 乳酸.
- In the specified Higher Tier model, blood flowing through muscles transports lactic acid to the liver, where it is converted back into glucose.
- Oxygen debt 氧债 is the extra oxygen the body needs after exercise to react with accumulated lactic acid and remove it from the cells.
- oxygen debt: Extra oxygen needed after exercise to handle accumulated lactic acid in the specified model.
- lactic acid: The product of anaerobic respiration in muscles in this course model.
Where is transported lactic acid converted back into glucose in the specified model?
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
In the specified model, lactic acid is carried in the blood to the liver, which converts it back into glucose. The microscope observes nothing here, and lung air spaces handle gases, not lactic acid.
Match each technical term to its precise meaning.
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- Explain the sequence using location and transport: muscle production, blood movement, liver processing and continued oxygen demand.
- The examination model supports explaining raised breathing during recovery.
- It does not imply that all oxygen consumed during exercise was absent or that every recovery process is the same chemical reaction.
In the lab: Interpret supplied recovery oxygen-use data against a stated resting baseline. For equal observation intervals, subtract the resting requirement from each interval and total the extra volumes. This is an evidence model, not an invitation to provoke oxygen debt or fatigue experimentally. Human observations stay voluntary, low-risk and supervised.
Which two habits make the investigation or model in this case more defensible?
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
Stating the conditions and assumptions lets others repeat the work exactly, and recording the supporting evidence lets them check the conclusion. Hiding disagreeing results removes the evidence that could challenge a wrong conclusion, and one measurement can never establish a wider claim.
Work from known quantities
- Known: resting oxygen use in a fictional model is 0.30 L per minute.
- Recovery use over three one-minute intervals is 0.90, 0.60 and 0.45 L.
- Extra oxygen = (0.90−0.30)+(0.60−0.30)+(0.45−0.30) = 1.05 L.
- Adding total use without subtracting baseline would overestimate the extra amount.
Your turn: Two one-minute intervals use 0.80 and 0.50 L oxygen; baseline is 0.20 L per minute. Calculate total extra oxygen.
Two one-minute intervals use 0.80 and 0.50 L oxygen; baseline is 0.20 L per minute. Calculate total extra oxygen.
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
The result is 0.9 L. Known: intervals use 0.80 and 0.50 L; baseline 0.20 L per minute. Extra = (0.80 - 0.20) + (0.50 - 0.20) = 0.60 + 0.30 = 0.9 L. The resting requirement must be subtracted first.
Check the conclusion and its limits
- An oxygen debt is a quantity of extra oxygen, not a financial cost or simply the time taken to rest.
- Blood transports lactic acid; it does not mean the heart converts it into glucose.
- This finite supplied record estimates only the extra oxygen included in its stated intervals.
Not true: Oxygen debt is calculated by adding all recovery oxygen without allowing for the resting requirement. Oxygen debt is the EXTRA oxygen needed above the resting rate during recovery. Adding total recovery oxygen without subtracting the baseline counts oxygen the body would have used anyway.
- When oxygen supply cannot meet vigorous muscle demand, incomplete glucose oxidation produces lactic acid.
- Explain the sequence using location and transport: muscle production, blood movement, liver processing and continued oxygen demand.
- Watch for: an oxygen debt is a quantity of extra oxygen, not a financial cost or simply the time taken to rest.
Oxygen debt is the EXTRA oxygen needed above the resting rate during recovery.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
True. Oxygen debt is the EXTRA oxygen needed above the resting rate during recovery. Adding total recovery oxygen without subtracting the baseline counts oxygen the body would have used anyway.
Extra oxygen needed after exercise to handle accumulated lactic acid in the specified model: write the technical term.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
oxygen debt means Extra oxygen needed after exercise to handle accumulated lactic acid in the specified model.