Which of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer?

Question

Quizplus · Accepted Answer

Na+ is a positively charged ion and is thus repelled by the hydrophobic region of the lipid bilayer. Diffusion is most effective for small, nonpolar molecules like butane or O2, which can easily pass through the hydrophobic interior of the membrane. CO2 is also relatively small and nonpolar, although it is slightly polar due to the presence of the double bond between the carbon and oxygen atoms.

Which of the Following Substances Would Have the Most Trouble