AP BIOLOGY

Detailed explanation-1: -Molecules that are polar or too big to diffuse across the plasma membrane using simple diffusion need extra help getting into or out of the cell.

Detailed explanation-2: -Facilitated Diffusion Requires Membrane Carrier Proteins Facilitated diffusion is also calledcarrier-mediated diffusion because a substance transported in this manner diffuses through the membrane with the help of a specific carrier protein.

Detailed explanation-3: -Sometimes, molecules cannot move through the cell membrane on their own. These molecules need special transport proteins to help them move across the membrane, a process known as facilitated diffusion.

Detailed explanation-4: -In facilitated diffusion, molecules diffuse across the plasma membrane with assistance from membrane proteins, such as channels and carriers.

Detailed explanation-5: -Simple diffusion does not require energy: facilitated diffusion requires a source of ATP.