AP BIOLOGY

Detailed explanation-1: -In facilitated diffusion, molecules diffuse across the plasma membrane with assistance from membrane proteins, such as channels and carriers. A concentration gradient exists for these molecules, so they have the potential to diffuse into (or out of) the cell by moving down it.

Detailed explanation-2: -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-3: -Facilitated diffusion therefore allows polar and charged molecules, such as carbohydrates, amino acids, nucleosides, and ions, to cross the plasma membrane.

Detailed explanation-4: -Channel proteins, gated channel proteins, and carrier proteins are three types of transport proteins that are involved in facilitated diffusion. A channel protein, a type of transport protein, acts like a pore in the membrane that lets water molecules or small ions through quickly.

Detailed explanation-5: -Transport of Substances Through Cell Membranes 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. That is, the carrierfacilitates diffusion of the substance to the other side.