Cell Membrane

What would happen if a cell dissolved in water, just like salt does? Thankfully, it doesn’t because it has a cell or plasma membrane that prevents it from dissolving in its watery environment.

This membrane controls the movement of substances in and out of the cell.

It is made of tiny phospholipid molecules, each with a ‘water-loving’ or hydrophilic head and two ‘water-repelling’ or hydrophobic tails.

These molecules are arranged in two layers, called a bilayer.

The hydrophilic heads face the water inside and outside the cell, while the hydrophobic tails stay in the middle.

This arrangement keeps the external water out and retains the internal water inside, helping the cell stay structurally intact.

The cell membrane is not like an open gate—it only allows certain substances to pass through. That is why it’s called a semi-permeable membrane.

All life forms, including plant, animal, and bacterial cells, have a cell membrane surrounding them.