Which of the following crosses lipid bilayers the slowest?
a. a small,
b. nonpolar molecule like oxygen (o₂)a small,
c. polar molecule like watera large,
d. polar molecule like glucose,
e. a sodium ion

d. polar molecule like glucose

Explanation:

The lipid bilayer of cells are composed basically by lipids and some other proteins. These proteins can act as carries to get in or get out from the cell some substances. Since the lipids are non polar substances, the non polar molecules can travel easily because they are similar substances, in the case of the polar substances they need some carriers and in the case that they don`t enter by a carrier, so the nature of the molecule is not so soluble in the lipid bilayer, in this way will cross at a slowest rate.