Breathing & Digestion: Better Together – Year 9
How Do Oxygen and Nutrients Power the Body? (PPT + Worksheet)

This lesson brings together the respiratory and digestive systems to show how the body releases and uses energy. Pupils define cellular respiration as an energy‑releasing chemical reaction, explain how glucose and oxygen meet at the cellular level, construct a diagram showing the movement of materials, and evaluate how homeostasis maintains stable nutrient and gas levels. This lesson strengthens students’ understanding of system interdependence and the science behind metabolism.

• Define cellular respiration as an energy‑releasing chemical reaction — aerobic respiration and its word equation.
• Explain how glucose and oxygen meet at the cellular level — transport via blood and diffusion into cells.
• Construct a diagram showing the movement of materials — oxygen in, carbon dioxide out, nutrients delivered.
• Evaluate how homeostasis maintains stable nutrient and gas levels — balancing supply, demand and internal conditions.

• KS3 Biology: Respiration, organ systems and interdependence
• Working Scientifically: Modelling, explanation and evaluation
  Some visuals in this resource were made with AI to help bring ideas to life and support student understanding.