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Biology journal Cambridge IGCSE 0610

Topic 3 of 21 · 2 of 2 modules ready

Movement into and out of cells

How substances and water cross cell membranes by diffusion, osmosis and active transport.

Modules

  1. A printed full stop seen close up; a magnifier circle shows human cheek cells, five or six across the dot.

    Module 1 · syllabus 3.1, 3.3 · 3 parts

    Diffusion and active transport

    Why are cells so small?

    Cut pink agar cubes of three sizes, put them in acid and time how long each takes to turn colourless. Cut a fresh set in half, compare surface area and volume, then test warmer and stronger acid.

    1. Diffusion and cell size Diffusion, surface area to volume ratio and the factors that change the rate of diffusion
    2. Diffusion in living things Diffusion through cell membranes: gases in the lungs and leaves, and dissolved substances
    3. Active transport Active transport against a concentration gradient, with protein carriers and energy from respiration

    Experiment Agar cubes in acid · time them, cut them, change one factor

    Open moduleExperimentTeacher pack
Syllabus statements for this topic · for teachers · 17 statements

Core for every pupil · Supplement also for Extended entry. Paraphrased from the Cambridge IGCSE Biology 0610 syllabus (2026–2028); check the official syllabus for exact wording.

3.1 Diffusion

Covered in Diffusion and active transport

  • 3.1.1Diffusion as net movement down a gradientC
  • 3.1.2Kinetic energy of particles drives diffusionC
  • 3.1.3Diffusion across the cell membraneC
  • 3.1.4Why diffusion of gases and solutes mattersC
  • 3.1.5Investigate factors affecting diffusion rateC

3.2 Osmosis

Covered in Osmosis

  • 3.2.1Water as a solvent in organismsC
  • 3.2.2Osmosis through partially permeable membranesC
  • 3.2.3Water enters and leaves cells by osmosisC
  • 3.2.4Investigate osmosis with dialysis tubingC
  • 3.2.5Investigate plant tissue in different solutionsC
  • 3.2.6Water pressure in cells supports plantsC
  • 3.2.7Osmosis in terms of water potentialS
  • 3.2.8Turgid, flaccid, plasmolysis and turgor pressureS
  • 3.2.9Water potential in water uptake and lossS

3.3 Active transport

Covered in Diffusion and active transport

  • 3.3.1Active transport against a gradient using energyC
  • 3.3.2Importance of active transport, e.g. root hairsS
  • 3.3.3Protein carriers in active transportS