Question

Which of the following will pass through a cell membrane most easily?

A) Ions
B) Water
C) Large proteins
D) Polar molecules

Answer 1

Water is the substance that will pass through a cell membrane most easily.

Step-by-step explanation:

Water

Small nonpolar molecules can easily diffuse across the cell membrane. However, due to the hydrophobic nature of the lipids that make up cell membranes, polar molecules (such as water) and ions cannot do so. Instead, they diffuse across the membrane through transport proteins.