Which of these substances is most likely to passively diffuse across the plasma membrane by dissolving in the membrane?
A)a cation
B)an anion
C) a nonpolar or nonionized molecule
D) a polar molecule

Question

Quizplus · Accepted Answer

Nonpolar or nonionized molecules can dissolve in the hydrophobic interior of the membrane and passively diffuse across the plasma membrane. Cations and anions have charges that interact with the charged head groups of the membrane, making it more difficult for them to pass through. Polar molecules also interact with the charged head groups of the membrane and cannot easily diffuse through the hydrophobic interior of the membrane.

Which of These Substances Is Most Likely to Passively Diffuse