Here's why:

* Glucose is a large, polar molecule. It cannot easily pass through the cell membrane's hydrophobic lipid bilayer.

* Facilitated diffusion utilizes transport proteins. These proteins act as channels or carriers, helping glucose move across the membrane.

* The process is passive. It doesn't require the cell to expend energy. Glucose moves down its concentration gradient, from an area of high concentration (like the bloodstream) to an area of low concentration (inside the cell).

Let me know if you'd like more details about facilitated diffusion or other transport mechanisms!