| Lesson Plan |
| Grade: |
Date: 25/02/2026 |
| Subject: Biology |
| Lesson Topic: describe and carry out investigations using simple respirometers to determine the effect of temperature on the rate of respiration |
Learning Objective/s:
- Describe the biochemical pathway of aerobic respiration and its main stages.
- Explain how temperature influences enzyme activity and the rate of respiration.
- Design and carry out a controlled experiment using a simple respirometer to measure respiration rates at different temperatures.
- Analyse the collected data to determine the temperature optimum and interpret the results in terms of enzyme kinetics.
- Communicate findings using appropriate graphs and scientific terminology.
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Materials Needed:
- Simple water‑filled respirometer (graduated syringe or glass tube)
- Potato slices (≈5 g) or other plant tissue
- Thermometers
- Water baths or temperature‑controlled containers (10 °C, 20 °C, 30 °C, 40 °C)
- Stopwatch or timer
- Data‑recording worksheets
- Graph paper or computer software for plotting
- Safety goggles and lab coat
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Introduction:
Begin with a short video showing how athletes' performance changes in hot weather to spark curiosity about temperature effects on metabolism. Review the steps of aerobic respiration that students have already studied. Explain that today they will build a simple respirometer, collect data at four temperatures, and use the results to identify the optimum temperature for respiration.
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Lesson Structure:
- Do‑now (5’) – Quick quiz on glycolysis and the Krebs cycle.
- Mini‑lecture (10’) – Recap respiration and introduce the temperature‑enzyme relationship.
- Demonstration (5’) – Show assembly of the water‑filled respirometer and how to read gas volume.
- Group experiment (30’) – Students set up respirometers with potato slices, run trials at 10 °C, 20 °C, 30 °C, 40 °C, recording volume every 2 min.
- Data analysis (10’) – Calculate rates, plot temperature vs. rate, identify the optimum.
- Check for understanding (5’) – Whole‑class discussion of results and sources of error.
- Exit ticket (5’) – Write one sentence summarising how temperature affects respiration rate.
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Conclusion:
Summarise that respiration rate rises with temperature to an optimum before falling due to enzyme denaturation. Collect the completed data sheets as an exit ticket to assess understanding. For homework, ask students to research how temperature influences respiration in ectothermic animals and prepare a short paragraph.
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