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CONCENTRATION GRADIENT

If a substance is more concentrated outside a cell than inside, the molecules will tend to diffuseinto the cell

If a substance is more concentrated inside thecell than outside, the molecules will tend todiffuse out of the cell

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The concentration of oxygen molecules isgreater outside the cellthan inside

So the oxygen moleculesdiffuse into the cell

CONCENTRATION GRADIENT9

SIZE OF CELLS

Smaller particles tend to diffuse faster than larger molecules

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DIFFUSION PATHWAY

Diffusion takes place more quickly through thin membranes because there is only a short diffusion pathway.The shorter the distance between the two regions , the faster the rate

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Diffusion is quicker if membrane has a large surface area

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SURFACE AREA

Increase in temperature increases rate of diffusion because particles have greater kinetic energy.

TEMPERATURE 13