Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Biology
Lesson Topic: Describe enzyme action: active site shape is complementary to its substrate and product formation.
Learning Objective/s:
  • Describe the lock‑and‑key model of enzyme action and explain how active‑site complementarity determines product formation.
  • Explain the four steps of an enzyme‑catalysed reaction (binding, transition‑state formation, product formation, release).
  • Analyse how temperature, pH, substrate concentration, enzyme concentration and inhibitors affect enzyme activity.
Materials Needed:
  • Projector and screen
  • Printed worksheet with enzyme diagrams
  • Lock‑and‑key model set (physical pieces)
  • Interactive simulation (e.g., PhET Enzyme Lab)
  • Coloured markers and whiteboard
  • Exit‑ticket cards
 Introduction:
Begin with a short video of a lock and key to capture interest. Ask students to recall how catalysts speed up reactions in everyday life and link this to enzymes. State that by the end of the lesson they will be able to describe how the enzyme’s active‑site shape matches its substrate and identify factors that influence reaction rates.
Lesson Structure:
  1. Do‑now (5'): Students answer a quick question on the role of catalysts on the board.
  2. Mini‑lecture (10'): Explain enzymes as biological catalysts and introduce the active‑site concept with a diagram.
  3. Model activity (12'): Using lock‑and‑key pieces, groups demonstrate complementarity and form an enzyme‑substrate complex.
  4. Guided practice (10'): Work through the reaction scheme E + S ↔ ES → E + P, labeling each step.
  5. Factors investigation (10'): Small groups analyse data tables on temperature, pH, substrate and enzyme concentration, and discuss inhibitor effects.
  6. Check for understanding (8'): Quick quiz via clickers/Kahoot; teacher reviews answers and clarifies misconceptions.
Conclusion:
Recap that enzymes accelerate reactions by providing a complementary active site that stabilises the transition state, and that optimal conditions are required for maximum activity. Students complete an exit ticket describing one factor that would reduce enzyme efficiency. For homework, assign a short worksheet applying the lock‑and‑key model to a new enzyme system.