1. Cell Membrane Notes Page 11 of Unit 3 Folder
E.Q. What is the structure and function of the cell membrane?

2. What is the cell membrane?
Cell membrane - a barrier that separates the cell from the outside environment.
Controls what goes into and out of the cell

3. What is the cell membrane made of?
Has a double layer of phospholipids
The heads are hydrophilic (like water)
The tails are hydrophobic (repel water)

4. What is the cell membrane made of?
There are also proteins and carbohydrates jammed in between the phospholipids

5. What is the cell membrane made of?
Fluid mosaic model – the membrane is fluid (floats like oil on water), yet is also made up of many different molecules (mosaic)

6. How do things move in and out of the cell?
The cell membrane is selectively permeable – that means it allows some, but not all, materials to cross it.
Things move from an area of higher concentration to an area of lower concentration – this is called a concentration gradient

7. 3 Ways Things Move In/Out of Cell
Passive transport – the movement of molecules across the membrane without using energy from an area of higher concentration to an area of lower concentration
Osmosis – the name given to the passive transport of WATER

8. 3 Ways Things Move In/Out of Cell
Facilitated diffusion – when transport proteins give molecules a ride through the membrane without using energy from an area of higher concentration to an area of lower concentration

9. 3 Ways Things Move In/Out of Cell
Active transport – The cells use energy to move molecules into the cell using proteins from an area of LOWER concentration to an area of HIGHER concentration.