Cell Membrane Is Made Up Of Molecules. However, every cell has a membrane and they all perform the basic function of protecting the cell and allowing molecules in and out of the cell. The phospholipids make the basic bag.
This is accomplished by the embedding of various protein molecules in and through the lipid bilayer (see figure below). The lipid bilayer acts as a barrier to the passage of molecules and ions into and out of the cell. The molecules in this bilayer are called phospholipids.
The bilayer is formed by the arrangement of phospholipids in a manner that their head regions (which are hydrophilic) face external environment as well as the internal cytosolic environment.
The membrane is partially made up of molecules called phospholipids, which spontaneously arrange themselves into a double layer with hydrophilic (“water loving”) heads on the outside and hydrophobic (“water hating”) tails on the inside. It is a selectively permeable cell organelle,allowing certain substances inside the cell while preventing others to pass through and thus is analogous to a barrier or gatekeeper in their function. The cell membrane, also called the plasma membrane, is a thin layer that surrounds the cytoplasm of all prokaryotic and eukaryotic cells, including plant and animal cells. This also controls entry and exit of substances as it also exhibits hydrophilic heads and hydrophobic tails.