The cell membrane is selectively permeable . It lets some substances pass through rapidly and some substances pass through more slowly, but prevents other substances passing through it at all. Some small molecules such as water, oxygen and carbon dioxide can pass directly through the phospholipids in the cell membrane.
Step-by-step explanation:
All cell are enclosed by a cell membrane , which is selectively preamble.Molecules can gain or lose an move into or out of cells by diffusion and active transport. cells gain or lose water by osmosis.Some small molecules such as water, oxygen and carbon dioxide can pass directly through the phospholipids in the cell membrane.
The phospholipid molecules are able to move around within the layers and give the cell membrane flexibility.