Cell BiologyVery High Exam FrequencyAQAEdexcelOCRWJEC

Cell Transport

Diffusion, osmosis, active transport, factors affecting transport, surface area to volume ratio, and practical investigations

What you'll cover

  • Diffusion definition and examples
  • Osmosis and water movement
  • Active transport using ATP
  • Factors affecting transport rate (concentration gradient, temperature, surface area, distance)
  • Surface area to volume ratio calculations
  • Multicellular organisms and exchange surfaces
  • Root hair cell adaptations
  • Alveoli gas exchange adaptations
  • Concentration gradients and equilibrium
  • Real-world transport examples (kidneys, lungs, small intestine)

Sample Flashcards

Define osmosis
The movement of water molecules from an area of high water concentration (low solute concentration) to an area of low water concentration (high solute concentration) through a semi-permeable membrane.
Define diffusion
The movement of particles from an area of high concentration to an area of low concentration down a concentration gradient. No energy is required (passive process).

Sample Questions

Which statement best describes diffusion?

  • A. The movement of particles from a region of low concentration to high concentration
  • B. The net movement of particles from a region of high concentration to low concentration
  • C. The movement of water molecules through a partially permeable membrane
  • D. The movement of particles using energy from respiration
1 markfoundation

Explain how osmosis causes a plant cell to become plasmolysed when placed in a concentrated sugar solution.

3 marksstandard

18

exam-style questions

20

revision flashcards

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