Question

Which of the following types of molecules are most likely to pass directly through the cell membrane's phospholipid bi-layer utilizing simple diffusion?

Question 4 options:

large, charged molecules


large, uncharged molecules


small, uncharged molecules


all of the above

Answer 1

The type of molecules most likely to pass directly through the cell membrane's phospholipid bilayer utilizing simple diffusion are **small, uncharged molecules**.

Simple diffusion occurs for small, nonpolar (or uncharged) molecules because they can easily move through the hydrophobic core of the lipid bilayer. Large or charged molecules typically require specialized transport mechanisms to cross the membrane.