I realize that this is as much a biology question as a chemistry one, but, man, that overlap... Anyway, I thought about this when I read in another forum that alcohol has no pH, or at the very least a neutral pH. I did a little more research about the toxic effects of alcohol and discovered that it disrupts membranes by displacing water molecules binding to the hydrophobic heads of phospholipids, and by that mechanism changes/disrupts some membrane proteins' functions, but it wasn't mentioned if alcohol could disrupt the membrane to the point of lysis and cell death. It's just something I've wondered about.