Movement of Substances through Membrane 2
Active Transport
- Active transport = the movement of dissolved ions of molecules across the cell membrane, against the concentration gradient. Energy (ATP) is required.
- For examples,
- ions intake by root hairs of a plant.
- ions intake by sea weeds and algae.
- potassium ions uptake by red blood cells from blood plasma.
- Importance of active transport:
- enables cells to selectively absorb or expel molecules and ions.
- enables particles to move against the direction of the concentration gradient.
- allow cells to take in or expel ions or molecules at different rates.
- Active transport requires both carrier proteins and energy to transport molecules or ions. The mechanism of active transport is shown below:
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| Active transport |
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