| Lesson Plan |
| Grade: |
Date: 25/02/2026 |
| Subject: Biology |
| Lesson Topic: describe the principles of cell signalling using the example of the control of blood glucose concentration by glucagon, limited to: binding of hormone to cell surface receptor causing conformational change, activation of G-protein leading to stimulat |
Learning Objective/s:
- Describe the sequence of events from glucagon binding to glycogen breakdown in hepatocytes.
- Explain how G‑protein activation leads to cAMP production and PKA activation.
- Illustrate signal amplification within the glucagon pathway.
- Analyze how the pathway restores blood glucose levels after hypoglycemia.
- Predict the effect of inhibiting key steps (e.g., adenylyl cyclase) on glucose homeostasis.
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Materials Needed:
- Projector and screen
- PowerPoint slides with pathway diagram
- Handout summarising the signalling steps
- Whiteboard and markers
- Clicker/polling software for quick checks
- Large poster paper for group mapping (optional model of a hepatocyte)
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Introduction:
Begin with a quick question: “What happens when your blood sugar drops after a fast?” Students recall prior learning about insulin and glucose regulation. Explain that today they will uncover how glucagon signals the liver to raise blood glucose, and outline the success criteria: identify each step of the signalling cascade and explain its purpose.
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Lesson Structure:
- Do‑now (5') – Students write a brief response to the opening question on sticky notes.
- Mini‑lecture (10') – Present glucagon release, receptor binding, and G‑protein activation using slides.
- Interactive pathway mapping (15') – In small groups, students place step cards on a poster to build the signalling cascade, labeling key molecules.
- Signal amplification discussion (10') – Teacher highlights amplification; students answer a poll question on the number of molecules affected.
- Case study analysis (10') – Given a low‑glucose scenario, groups predict the cellular response and justify each step.
- Formative check (5') – Exit ticket: “Write the immediate downstream event after adenylyl cyclase activation.”
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Conclusion:
Recap the seven‑step cascade, emphasizing how a single hormone‑receptor interaction triggers a large metabolic response. Collect exit tickets to assess understanding, and assign a short homework: create a one‑page flowchart of the glucagon pathway with brief annotations.
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