1. Plasma Membrane Structure and Function

2. Membrane Functions Protection Communication Recognition
Selectively allow substances in
Respond to environment
The last two can be combined and reworded as maintaining homeostasis

3. How does the cell Membrane maintain homeostasis?
Separating the outside environment from the inside of the cell
Regulating what goes in and out of the cell
Cell membrane is Selectively Permeable
Lets some molecules pass through while keeping other molecules out
Think about it!
What goes in?
What leaves?

4. How molecules enter and leave the cell is related to cell membrane structure
Look at all of the parts. They all play a specific role.

5. Cell Membrane structure
Phospholipid bilayer
hydrophilic heads-like water (polar)
hydrophobic tails-don’t like water (nonpolar)
Phospholipids are in motion!

6. embedded in the cell membrane
Cholesterol
Keeps the membrane fluid at low tempertures
Keeps the phospholipids from moving too fast at high temperatures
Transport Proteins
Passage way for food, water and ions
Receptors Proteins
Receives chemical messages from outside the cell and sends them inside
Marker Proteins
Name tags that lets the cell know that the cell belongs to you
Anchor Proteins
Keeps other proteins in the membrane from moving