| Role | Barrier |
| Released | late 1600s |
The Cell Membrane, or Plasma Membrane, serves as the cell's outer boundary. All cells contain one, including plant cells. It regulates the passage of materials in and out of the cell and maintains ceullar integrity.
Structure
It is composed of a phospholipid bilayer with embedded proteins, namely Integral and Peripheral.
Materials are transported through a membrane in two ways: passive and active. Passive transport happens from high to low concentrations, and active happens from low to high.
Synergy
Protects and contains every other organelle in the cell.