1. Protecting the cell
since…forever

2. Recall Check…Do you remember?
What are two parts that every lipid has to have?

3. Cellular Boundaries
A thin, flexible barrier known as the cell membrane surrounds all cells.
The make-up of cell membranes is a double layer of lipids called phospholipids.

4. The functions of cell boundaries.
The cell membrane:
Controls what enters and leaves the cell
Protects and supports the cell

5. Phospholipid Structure
a closer look

6. Phospholipids and Water…
HYDROPHILIC
HYDROPHOBIC

7. Hydrophilic versus Hydrophobic
Hydro: water
Philic: to love; to want; to desire
Phobic: to fear; to hate; to loathe
Hydrophilic: to love and desire being around water
Hydrophobic: to fear and loathe being around water

8. Structure Equals Function
The special structure of the bilayer allows for there to be a inside and an outside.
The fatty acid tails hate water and only like themselves.

9. Plasma Membrane

10. Phospholipid Bilayer = Cell Membrane = Plasma Membrane
All three of these names identify the same part of the cell.
They can all be used interchangeably.
The diagram shows:
Phospholipid Bilayer
Cell Membrane
Plasma Membrane

11. Fluid-Mosaic Model Fluid: able to flow easily
Mosaic: a picture or pattern produced by arranging together small colored pieces of hard material, such as stone, tile, or glass
The cell membrane/plasma membrane/phospholipid bilayer are called a fluid mosaic because it is constantly moving and made up of a bunch of stuff.

12. Cell Membrane

13. Plasma Membrane: Carbohydrates
Surface carbohydrates on a cell membrane act as a license plate.
Carbohydrates are linked to proteins or lipids act as sticky place of attachment points for cells.

14. Cell Membrane: Lipids
Phospholipids are the main ingredient in the cell membrane.
Lipids can also be used by as anchor points for carbohydrates.
Cholesterol can be used as a way to keep F.A.Ts from tangling up.

15. Cholesterol

16. Phospholipid Bilayer: Proteins
Integral proteins: proteins that go all the way through the cell membrane.
Peripheral proteins: proteins that are just on the inside or outside of the cell membrane
Proteins serve several
functions throughout
the cell membrane.
Transport
Attachment
Cellular Communication