Lesson Plan

• Describe the main proteins (actin, myosin, troponin, tropomyosin) and ions (Ca²⁺, ATP) involved in skeletal muscle contraction.
• Explain the eight‑step sequence of a contraction cycle from excitation‑contraction coupling to relaxation.
• Interpret a sarcomere diagram to show how calcium binding and ATP hydrolysis produce the power stroke.

• Projector and computer with slide deck
• Animated video of the sliding filament model
• Printed handouts of the sarcomere diagram and summary table
• 3‑D sarcomere model or large poster
• Whiteboard and markers
• Kahoot/quiz platform for quick check

Begin with a short video of a sprinter’s leg muscles contracting, asking students what they think makes the fibres shorten. Review prior knowledge of actin‑myosin interaction and set the success criteria: students will be able to name key molecules and trace the contraction cycle.

1. Do‑now (5 min): Write a quick paragraph on how muscles generate movement; share ideas.
2. Mini‑lecture with slides (10 min): Introduce actin, myosin, troponin, tropomyosin, Ca²⁺ and ATP.
3. Animated demonstration (8 min): Show the sliding filament model; pause to discuss the role of each component.
4. Guided diagram lab (12 min): Students label a sarcomere handout, matching each step of the contraction cycle.
5. Role‑play activity (10 min): Groups act out the eight steps, each student representing a molecule or ion.
6. Formative quiz (5 min): Kahoot questions on sequence and energy use.
7. Recap & exit ticket (5 min): Students write one thing they mastered and one lingering question.

Summarise how Ca²⁺ binding shifts troponin‑tropomyosin, allowing myosin heads to perform the power stroke powered by ATP hydrolysis, and how removal of Ca²⁺ leads to relaxation. Collect exit tickets and assign homework: read the textbook section on muscle physiology and complete the worksheet labeling the contraction cycle.