Lesson Plan

• Describe the Bohr effect and how changes in pH and CO₂ alter haemoglobin’s affinity for O₂.
• Explain why the Bohr shift is essential for efficient O₂ delivery and CO₂ removal.
• Analyse factors that cause right‑ or left‑shifts of the oxygen‑haemoglobin dissociation curve.
• Apply the concept to predict gas‑transport responses during exercise or altered breathing patterns.

• Projector or interactive whiteboard
• PowerPoint slides showing dissociation curves
• Handout summarising the Bohr shift mechanism
• Physical model of haemoglobin (optional)
• Whiteboard and markers
• Exit‑ticket slips for the conclusion

Begin with a quick image of athletes breathing heavily and ask students why muscles need more oxygen during exercise. Review prior knowledge of haemoglobin’s role in gas transport. State that today they will identify how pH and CO₂ regulate haemoglobin affinity and why this matters.

1. Do‑now (5'): Students list ways O₂ is transported in blood; share answers.
2. Mini‑lecture (10'): Explain the Bohr shift mechanism with the chemical equation and illustrate right‑shift on the dissociation curve.
3. Guided activity (12'): In pairs, analyse a table of factors (pH, CO₂, temperature, 2,3‑BPG) and predict curve direction; report findings.
4. Application demo (8'): Show a short video of exercise physiology; discuss how the Bohr effect meets tissue demand.
5. Check for understanding (5'): Quick quiz using clickers or hand‑raise to confirm key concepts.

Summarise that the Bohr shift enables haemoglobin to release O₂ where metabolism is high and to aid CO₂ transport, helping maintain blood pH. Students complete an exit ticket stating one real‑life example of the Bohr effect. Assign a short homework: write a paragraph predicting how hyperventilation would affect the dissociation curve.