1. Cell Membrane Transportation
How do cells transport ions, materials, and solutes?

2. Solutes
1. A solute is anything that can be dissolved or mixed with water.
Examples:
Salt
Sugar

3. Cell Membrane Transportation Mechanics
There are four components contributing to solutes traveling through cell membranes 2.
Energy
Lipid Bilayer
Proteins
Osmotic Pressure

4. Lipid Bilayer Thin elastic structure 7.5-10 nanometers thick
Cytoplasm
Extracellular Fluid
Thin elastic structure nanometers thick
Sheet of phospholipids and cholesterol, with some proteins

5. Lipid Bilayer - Diagram

6. Parts of the Membrane
3. Phospholipids- form the hydrophobic barrier around the cell
Proteins- act as channels to let stuff in
Antigen/ Marker- act as cell “name tags”

7. Lipid Bilayer - Permeability
4. Permeability- The ability to travel through the cell membrane
5. Selectively Permeable – membrane is specific about what does/doesn’t enter

8. Lipid BiLayer
Some molecules easily cross cell membranes using their motion and no additional energy
Water, oxygen, carbon dioxide
Ions, larger polar molecules, and larger molecules (some proteins) cannot easily cross membrane and need energy to do make the journey

10. Diffusion 6. Diffusion- Movement of molecules across a membrane
7. Passive process – no energy required
8. Molecules always move from higher to lower concentrations (down concentration gradient)
Movement until equal concentrations exist
Larger molecules move more slowly

11. Diffusion
Diffusion Animation

12. Factors Affecting Diffusion
9. Molecule size & Concentration gradient

13. Osmosis
10. Osmosis- The diffusion of water
11.

14. Osmosis- environments
12. Isotonic- neither cell nor solution gain/lose water
13. Hypotonic – causes net flow of water into cell
14. Hypertonic – causes net flow of water out of cell

15. Osmosis
15.
16.
17.

16. Active Transport - Definition
18. Active Transport- Molecules move against concentration gradient and Energy is required

17. Active Transport - Examples
19. Endocytosis – taking material into the cell &
Exocytosis – taking material out of the cell

18. Active Transport - Endocytosis
Low Density Lipoproteins (LDL) being brought into cellular lysosomes

19. Active Transport - Exocytosis
Insulin granule being removed from the pancreas

20. Conclusion There are two main types of Diffusion
Passive Transport- which requires no energy- Osmosis is an example of Passive Transport
Active Transport- requires energy, makes solutes go against their concentration gradients.