Cell membrane
ScienceDefinition
The cell membrane is a thin, flexible barrier made of a phospholipid bilayer that surrounds every cell. It controls what enters and exits the cell, maintaining homeostasis through selective permeability.
Examples
- The cell membrane allows oxygen and carbon dioxide to pass through freely by diffusion
- Receptor proteins on the membrane surface let hormones like insulin communicate with the cell
- White blood cells use their membranes to engulf bacteria through phagocytosis
Key Fact
The fluid mosaic model describes the membrane as a dynamic structure of phospholipids, proteins, cholesterol, and carbohydrates.
Study This Concept
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