The membrane is selectively permeable because substances do not cross it indiscriminately. Some molecules, such as hydrocarbons and oxygen can cross the membrane. Many large molecules (such as glucose and other sugars) cannot. Water can pass through between the lipids.

The selectively permeable membrane is the outer structure of a cell that dictates what can come in and out of it. It’s important that the membrane is selective because it may let in harmful substances. When molecules freely move from an area of high concentration to lower concentration .

Cell membranes are semipermeable, which means molecules can move through them. This is pretty important for cells to survive. Osmosis is where solvent molecules (usually water) move from one side of a cell membrane to the other. The cell removes the molecules as soon as they arrive to keep osmosis happening.

noun. A membrane that is selectively permeable, i.e. being permeable to only certain molecules and not to all molecules. Supplement. An example of such membrane is the cell membrane wherein it allows passage of only certain types of molecules by diffusion and occasionally by facilitated diffusion.

Q. What is another term for “selectively permeable”? Porous.

Sea water is hypertonic to your cells and will only further dehydrate you. Sea water is too isotonic to your cells and you will absorb too much water. The salt will cause high blood pressure and you will die from a stroke.

The hydrophobic, or “water-fearing,” part of a phospholipid consists of its long, nonpolar fatty acid tails. The fatty acid tails can easily interact with other nonpolar molecules, but they interact poorly with water.

cell membrane

plasma membrane

A permeable membrane lets everything through, similar to how you let everyone into your home for the block party. An example of a permeable membrane in nature is the cell wall in plant cells. Cell walls provide support and protection for plant cells. They are fully permeable to water, molecules, and proteins.