| Lesson Plan |
| Grade: |
Date: 25/02/2026 |
| Subject: Biology |
| Lesson Topic: describe the molecular structure of the polysaccharides starch (amylose and amylopectin) and glycogen and relate their structures to their functions in living organisms |
Learning Objective/s:
- Describe the molecular structures of amylose, amylopectin, and glycogen, including their α‑1,4 and α‑1,6 glycosidic linkages and degree of branching.
- Compare the solubility and physical properties of the starch components and glycogen.
- Explain how structural differences determine the storage and rapid‑mobilisation functions in plants and animals.
- Predict the action of key enzymes (α‑amylase, debranching enzyme) on each polysaccharide.
- Analyse a structure‑function table to justify why glycogen is suited for quick energy release.
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Materials Needed:
- Projector and screen
- PowerPoint slides with amylose, amylopectin, and glycogen diagrams
- Printed handouts of the comparative structure‑function table
- Glucose‑polymer molecular model kits
- Worksheet for guided activity
- Whiteboard and markers
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Introduction:
Begin with a quick visual of a sprouting seed and a sprinting athlete to highlight the need for rapid energy release. Ask students what they already know about glucose and simple sugars, then link that knowledge to larger carbohydrate polymers. State that by the end of the lesson they will be able to describe the structures of starch and glycogen and explain why those structures matter.
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Lesson Structure:
- Do‑now (5 min): short quiz on monosaccharides and glycosidic linkages.
- Mini‑lecture with slides (10 min): introduce amylose, amylopectin, and glycogen structures.
- Guided modelling (12 min): students build polymer models, identify α‑1,4 and α‑1,6 bonds.
- Comparative table activity (8 min): groups fill a table linking structural features to functions.
- Enzyme video demonstration (5 min): show α‑amylase and debranching enzyme action.
- Think‑pair‑share (5 min): discuss why glycogen’s higher branching is advantageous.
- Formative check – exit ticket (5 min): write one sentence summarising a structure‑function relationship.
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Conclusion:
Recap the key differences in branching and how they relate to storage roles in plants and animals. Collect the exit tickets to gauge understanding, and assign a homework task to create a labelled diagram of either amylopectin or glycogen and write a brief explanation of its functional significance.
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