1. Cell Membrane Structure

2. Fluid Mosaic
The cell membrane is often referred to as a ‘Fluid Mosaic”
Fluid, because the membrane is not static. It is constantly moving and rearranging itself.
Mosaic, because it is made up of a variety of different components that are specifically arranged.
Video: The inner life of the 0:22

3. Phospholipids The cell membrane is primarily made up of phospholipids
Explain hydrophobic and hydrophilic

4. Arrangement of phospholipids

5. Cell membranes are phospholipid bilayers

6. Saturated and unsaturated fats
No double bonds Cis double bonds/trans fats

8. Trans fats in the news
FDA to ban trans fats

9. Cholesterol

10. Unsaturated fats and cholesterol
Bend fatty acid tails and membrane embedded cholesterol both lead to membrane fluidity.
For animals that live in colder climates, unsaturated fats and cholesterol are beneficial and even necessary for proper membrane function.

11. Summary Questions
Cell membranes are sometimes referred to as a ______________. This is because they are dynamic arrangements of different elements.
Cell membranes are made up of a special lipid known as a ___________.
Phospholipids have _________ heads and __________ tails.
These hydrophilic/phobic interactions create a double layer of phospholipids, also known as a ______ _________.
Unsaturated fats (trans and cis double bonds) and cholesterol make membranes more ________.