* Aquaporins are passive transport channels: They facilitate the movement of water across cell membranes down its concentration gradient. This means water moves from an area of high concentration to an area of low concentration, and no energy is required.
* Active transport requires energy: Active transport mechanisms use energy, often in the form of ATP, to move molecules against their concentration gradient (from low to high concentration).
Examples of active transport:
* Sodium-potassium pump
* Proton pumps
* Glucose transporters
In summary: Aquaporins are passive transport channels, while active transport requires energy to move molecules against their concentration gradient.
