Question

Is osmosis an example of facilitated diffusion or active transport?

Answer 1

Active transport is a process that requires energy, often because you're moving a substance against its concentration gradient.

Osmosis is the movement of water from an area of low solute concentration to an area of high solute concentration (movement along its "concentration gradient"). Water is a highly polar molecule and so does not readily diffuse across cellular membranes, which are hydrophobic due to their lipid composition. Therefore, you get protein channels like aquaporins that span the membrane and permit movement of water into or out of the cell as necessary. In a biological context, osmosis is an example of facilitated diffusion.

Answer 2

so it's an example of active transport?

Answer 3

Active transport is simply transport against an electrochemical gradient. The cell requires additional energy. One example of active transport would be protein pumps, specifically, the sodium-potassium pump. Steps:
1. Ions or other molecules can bind to binding sites in the protein
2. A phosphate group from ATP also binds to the protein, changing its shape
3. Then the ions or molecules are released to the other side of the membrane

Answer 4

As I explained in my answer above, osmosis is an example of facilitated diffusion.