O2 vs CO2 passing through cell membrane

[superdawg]

I have a question that asks which substance will pass through a plain (no channels, etc.) lipid bilayer cell membrane the fastest. The answer is CO2.

 

My guess was O2. I figured since CO2 contains two different atoms, you'd have more opportunity for a partial dipole across the molecule. It's also larger.

[Joshua201]

I have a question that asks which substance will pass through a plain (no channels, etc.) lipid bilayer cell membrane the fastest. The answer is CO2.

 

My guess was O2. I figured since CO2 contains two different atoms, you'd have more opportunity for a partial dipole across the molecule. It's also larger.

think it has to do with the spartial diplacement of molecules