Question

Facilitated diffusion involves the movement of

• A. Small, charged and polar molecules with the help of ATP.
• B. Small, neutral and nonpolar molecules with the help of ATP.
• C. Small, neutral and nonpolar molecules without an ATP requirement.
• D. Small, charged and polar molecules without an ATP requirement.

Answer 1

The correct option is D Small, charged and polar molecules without an ATP requirement.

Facilitated diffusion is the process in which the transport of the molecules takes place across the cell membrane with the help of the concentration gradient. The cell membrane allows the passage of the small, charged and polar molecules through the channel proteins due to the difference in the concentration of the molecules inside and outside of the cell membrane. Since the process takes place on its own due to the difference in the concentration, there is no requirement of the external energy in the form of ATP.

Thus, the correct answer is option D.