Phopholipids

These are the base of the cell membrane. Without them, there would be no cell membrane. Other molecules make it easier for transport or just modify the cell membrane (give properties).

Membrane Proteins

Integral

These proteins are anchored into the cell membrane. Thus, they must have at least one hydrophobic region.

Transmembrane

These are a type of integral protein that extends from one side of the membrane to the other. These are what most integral proteins are. They have a hydrophobic and hydrophilic region.

They are usually an alpha helix.

Peripheral

These proteins are found on the surfaces of the membrane. Thus, they are loosely attached and do not have hydrophobic regions.

They can be attached to phospholipids or integral proteins.

Carbohydrates

They serve as the identity of each cell and allow cells to recognize each other. Due to this, immune system will not attack them.

Always on extracellular side.

Glycoproteins

carbohydrates attached to proteins

Glycolipids

carbohydrates attached to phospholipids