English National Curriculum - Science

Diffusion

Mission Objectives

Define diffusion and describe how it occurs across cell membranes

Explain the effect of surface area, temperature, and concentration gradient on diffusion rate

Describe adaptations of exchange surfaces in mammals, fish, and plants that maximise the rate of diffusion

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Lesson Plan

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Keywords

Words and meanings to learn

net-movement

The overall direction that particles move, even though they are all moving randomly

surface area to volume ratio

A measurement that affects how quickly substances can diffuse into cells.

concentration

The amount of a substance in a given volume, affecting how quickly diffusion occurs.

particles

Small, minute pieces that make up solids, liquids, and gases.

diffusion

The process by which particles spread from an area of high concentration to an area of low concentration.

This lesson has been written by

Samantha Batch

Samantha is an accomplished science educator whose current work centres on curriculum design and professional development, supporting teachers to deliver high-quality science education through evidence-informed approaches. She is a former Head of Chemistry and Sixth Form Tutor with extensive Key Stage 4 and 5 experience, and has worked as an AQA examiner, giving her valuable insight into assessment standards and what students need to succeed.

Samantha has written the complete KS4 Science curriculum, fully aligned with the AQA GCSE Science: Trilogy specification. Covering biology, chemistry and physics, the curriculum is carefully sequenced so that students build knowledge cumulatively and see clear connections between concepts across the three sciences. Drawing on her experience as an examiner and on research into effective teaching, she has designed it to embed retrieval practice, clear explanation, worked examples and the required practicals throughout, preparing students for the demands of the GCSE exams. Grounded in the realities of the classroom, the curriculum is rigorous for students and manageable for busy teachers.

In her spare time, Samantha enjoys playing the accordion with her local orchestra and has recently taken up cricket. 

Required Resources

PowerPoint slides and visual aids (particle diagrams, SA:Vol ratio tables)

Agar jelly cubes with sodium hydroxide and phenolphthalein indicator

Beakers of hydrochloric acid

Rulers, stopwatches, scalpels, tweezers

Practical worksheet with pre-filled and blank SA/Vol tables

Adaptation card sort or fact sheet on exchange surfaces (lungs, gills, leaves, intestines)

Differentiated challenge questions for stretch and application

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