How does ethanol enter and disrupt cell membranes?

[clouded.perception]

I'm told that ethanol crosses a cell membrane very easily and can screw up the inner workings of the cell. But ethanol is very hydrophilic, so shouldn't it have a really tough time crossing a phospholipid membrane? does it hijack a transport protein or something?

 

[Spirochete]

Remember that small, highly polar (but uncharged) molecules such as water are able to diffuse almost freely through the lipid bilayer. Ethanol is larger than water, but not by a lot. Also, ethanol is significantly less polar than water because it has a two carbon alkyl group on it. Also, it only has two locations where it can hydrogen bond whereas water has three.

 

[oswaler]

Yes, you are correct that ethanol is hydrophilic and should have difficulty crossing a phospholipid membrane. However, ethanol is also a small molecule and can diffuse through the membrane's hydrophobic core. Additionally, ethanol can interact with and disrupt the structure of the phospholipid bilayer, making it easier for it to cross.

Ethanol can also hijack transport proteins, such as aquaporins, which are responsible for transporting water and small molecules across the cell membrane. This allows ethanol to enter the cell more easily and potentially cause damage to the cell's inner workings.

Furthermore, the concentration of ethanol outside the cell can also affect its ability to cross the membrane. If the concentration of ethanol is high, it can create a concentration gradient that drives it into the cell.

Overall, while ethanol may have difficulty crossing a cell membrane due to its hydrophilic nature, it has various mechanisms that allow it to enter the cell and potentially harm its inner workings. This is why it is important to consume ethanol in moderation and to be aware of its effects on the body at a cellular level.