Cell membranes serve as barriers and gatekeepers. They are semi-permeable, which means that some molecules can diffuse across the lipid bilayer but others cannot. ... Specialized proteins in the cell membrane regulate the concentration of specific molecules inside the cell.

Is semipermeable membrane a cell?

The cell membrane is semipermeable (or selectively permeable). It is made of a phospholipid bilayer, along with other various lipids, proteins, and carbohydrates. ... The unique structure of the cell membrane allows small substances (like oxygen or carbon dioxide) to easily pass through.

How is the semipermeable membrane like a cell membrane?

A semipermeable membrane is a layer that only certain molecules can pass through. ... While water and other small molecules can slip through the gaps between the phospholipid molecules, other molecules like ions and large nutrients cannot force their way into or out of the cell.