1. Cell Membrane Strucutre
1. Phospholipid bilayer
a. hydrophilic heads point out (phosphate)
b. hydrophobic tails in center (fatty acid)

2. Cell Membrane Strucutre
2. Cholesterol
a. keeps p-lipid from sticking together
b. is a lipid so its hydrophobic

3. Cell Membrane Structure
3. Transport proteins
a. protein tunnels through bilayer
b. only let specific things in/out
c. can open and close

4. 2 Types of Cellular Transport
1) Passive Transport = no energy needed
mol. flow high concentration  low conc.
2) Active Transport =
takes energy
molecules pumped
Low conc.  high conc.
Exocytosis/endocytosis

5. 3 Types of Passive Transport all high conc.  low conc.
1) Diffusion
(any molecule, random motion)
2) Facilitated Diffusion
(diffusion through transport protein)
3) Osmosis
(diffusion of water through membrane)

6. Diffusion

7. Facilitated Diffusion
Molecules too big to fit btwn phospholipids
must go through transport protein

8. Osmosis
Diffusion of water
must cross a membrane

9. 3 Types of Active Transport can be low conc.  high conc.
1) Protein pumps
(transport protein pushes molecules
against conc. gradient)
2) exocytosis
(cell membrane spits out molecules)
3) endocytosis
(cell membrane takes in molecules)

10. Protein Pumps
Protein pushes molecules into areas where they are in high concentration.
ATP is the
energy used

13. Terms for solute concentrations
substance dissolved in water (sugar)
Hypertonic solution =
high concentration
of solute
Hypotonic solution =
lower concentration

14. Isotonic solutions =
same concentration of solute
if mol. can pass through membrane….
they will do so until equal conc. on each side