Cambridge IGCSE·Co-ordinated Sciences 0654·Biology
Movement In Out Of Cells
Key knowledge — Movement In Out Of Cells
Key facts & rules
- Diffusion: net movement of particles from HIGH to LOW concentration — no energy needed (passive).
- Osmosis: net movement of WATER molecules from high water potential (dilute solution) to low water potential (concentrated solution) through a selectively permeable membrane — passive.
- Active transport: movement from LOW to HIGH concentration — requires ENERGY (ATP) and carrier proteins.
- Factors affecting diffusion rate: concentration gradient, surface area, temperature, distance, molecule size.
- Turgid cell: full of water, firm (plant cells in dilute solution).
- Plasmolysed cell: loses water, membrane pulls away from cell wall (plant cells in concentrated solution).
- Crenated/shrunken: animal cells in concentrated solution (they have no cell wall).
IGCSE Biology — Movement in & out of cells
568 Cambridge IGCSE 0654 biology past paper questions on movement in & out of cells, organised by subtopic. Pick a subtopic to start practising.
About movement in & out of cells on IGCSE 0654
Diffusion, osmosis and active transport — how substances cross cell membranes, and how surface area, concentration gradient and temperature affect the rate.