Why do high alcohol concentrations affect cell membranes more than low alcohol concentration? ?
Osmosis is the movement of water molecules from an area of low solute concentration to an area of high solute concentration across a partially permeable membrane until a concentration equilibrium is reached. In this case, the cell membrane is acting as the partially (or selectively) permeable membrane. I’m guessing that there is normally some alcohol in the cytoplasm. If this is the case, then, if there is a high concentration of alcohol (higher than that in the cytoplasm) then water from the cell will move out of the cell by osmosis. As animal cells do not have a rigid cell wall, this will cause the cell to shrivel. If there is a fairly equal concentration of alcohol on either side of the membrane, then there will be little or no movement of water particles across the membrane, allowing the cell to remain normal.
