Cell Membrane Facts


The cell membrane is the boundary between a living cell and its outside environment, and it is responsible for regulating what molecules pass into and out of the cell. Cell membranes can be thought of as fluid mosaics of phospholipids and proteins.


  • Phospholipids are the main component of cell membranes. Each phospholipid molecule has a hydrophilic (attracted to water) head region and a hydrophobic (repelled from water) tail region. To form a membrane, phospholipids are arranged in a bilayer with the hydrophobic tails pointing inside the membrane and the hydrophilic heads facing out.


  • Phospholipids are constantly moving laterally within the membrane. Cholesterol helps keep membrane fluidity constant by slowing down the movement of phospholipids at high temperatures and by preventing them from packing close together at lower temperatures.


  • Cells recognize each other by the carbohydrates in their cell membranes. Cell-cell recognition (how one cell recognizes other cells) is important in sorting different types of cells into organs during embryonic development, and it is how the immune system is able to identify and attack foreign cells.


  • Cell membranes are selectively permeable. Hydrophobic molecules dissolve in the phospholipid bilayer and easily pass through the membrane. Other molecules can be brought into the cell through transport proteins that span the membrane.


  • Cell membranes are about 8 nanometers thick.

Related Searches


  • Biology (8th Edition); Campbell and Reece; 2008
Promoted By Zergnet


You May Also Like

  • Facts About Plasma TVs

    With so many options available now, if you're shopping for a new TV you may feel overwhelmed by the glut of information....

  • Structure of a Cell Membrane

    Cells in the human body draw on materials from their environments to sustain cellular functions. The structure of a cell membrane plays...

  • Interesting Facts about Plant Cells

    Plants manufacture their own food, which makes them unique among living organisms. Plants' cells are designed to support the function of food...

  • What Are the Primary Functions of Phospholipids?

    Cells are important components of animal bodies. They are the basic building blocks of life. Fats and lipids, such as phospholipids and...

  • Osmosis Facts for Kids

    Osmosis is a scientific concept typically taught to children during elementary school. In osmosis, a solvent passes through a membrane from one...

Related Searches

Check It Out

How to Build and Grow a Salad Garden On Your Balcony

Is DIY in your DNA? Become part of our maker community.
Submit Your Work!