* Plasma membranes are selectively permeable: They control what enters and exits the cell. They are primarily composed of a phospholipid bilayer with embedded proteins.
* N₂O is a small, non-polar molecule: This makes it relatively easy to diffuse across lipid membranes.
* N₂O is not highly soluble in water: Plasma membranes are mostly composed of water, and N₂O's low solubility means it doesn't readily dissolve in the membrane's environment.
* N₂O is not a substrate for any membrane transport proteins: These proteins are crucial for the movement of large, polar molecules across the membrane.
In summary: While N₂O is small and non-polar, its low solubility in water and lack of transport mechanisms prevent it from diffusing efficiently across a plasma membrane.
Therefore, nitrous oxide gas molecules do not significantly diffuse across a plasma membrane.
