Written by the Fiveable Content Team โข Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 examโขWritten by the Fiveable Content Team โข Last updated September 2025
Definition
A plasma membrane is a thin, flexible barrier that surrounds all cells and separates the cell's interior from its external environment. It controls what enters and leaves the cell.
Related terms
Lipid Bilayer: This is a universal component of all cell membranes. The lipid bilayer acts as a sturdy barrier that prevents random substances from entering or leaving the cell.
This is a type of biological or synthetic membrane that will allow certain molecules or ions to pass through it by diffusion and occasionally specialized 'transport proteins'.
This is an additional layer present outside the plasma membrane in plant cells, fungi, bacteria, etc., providing these cells with structural support and protection.