Comparing diffusion, osmosis and active transport

In animals, plants and microorganisms, substances move into and out of cells by diffusion, osmosis and active transport.

ProcessDescriptionSubstances transportedEnergy required
DiffusionSubstances move from a high to a lower concentration down a concentration gradientCarbon dioxide, oxygen, water, food substances, wastes, eg ureaNo
OsmosisWater moves from a high to a lower concentration across a partially permeable membrane and down a concentration gradientWaterNo
Active transportSubstances more from low to higher concentration up a concentration gradientMineral ions into plant roots. Glucose from the gut into intestinal cells, from where it moves into the bloodYes
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