Answer:
Proteins
Explanation:
Facilitated diffusion is the transport of substances via some membrane proteins. The cell membrane has proteins embedded in the bilayer of phospholipids. Some of these membrane proteins serve as carriers or channels. These channel proteins make the path to facilitate the diffusion of large or charged particles such as ions which cannot pass the hydrophobic core of the membranes. Likewise, the carrier proteins undergo conformational changes to transport large substances across the membrane.
