The cell membrane, also known as the plasma membrane, has several vital functions:
- It acts as a protective barrier that separates the interior of the cell from the external environment.
- It is selectively permeable, meaning it controls the movement of substances in and out of the cell, allowing essential nutrients to enter while keeping harmful substances out.
- The membrane regulates the transport of materials by both passive transport (no energy needed) and active transport (energy required).
- It maintains the cell's structural shape by anchoring the cytoskeleton.
- The cell membrane is involved in cell communication and signaling through membrane proteins that act as receptors for hormones and other signaling molecules.
- It also serves as an attachment surface for extracellular structures and helps cells adhere to each other to form tissues.
Overall, the cell membrane functions as a dynamic and complex gatekeeper essential for the cell's survival, protection, and communication. It maintains homeostasis by selectively regulating what enters and exits the cell. This summary integrates information from several sources describing the cell membrane's main roles and its selective permeability function.
