1. 6.3 Transport

2. 6.3 Transport: Predict the results
What do you predict will happen if food coloring is dropped into a beaker of water?
Where are the molecules most concentrated to start?
Where are the molecules less concentrated to?
What is Diffusion?
The movement of molecules from a high concentration to a low concentration.

3. 6.3 Transport
KEY CONCEPT Materials move across membranes because of concentration differences.
What is a concentration gradient?
A difference in molecule concentration
Molecules move down a concentration gradient.
Think of a slide.
Would energy be needed?

4. How is Diffusion Important for cells or your Body?
For Cellular Transport
Medications, digestion, oxygen, carbon dioxide.

5. 6.3 Passive Transport Passive transport :
Molecules can move across the cell membrane through passive transport.
Does not require energy input from a cell.
There are three types of passive transport.
Simple diffusion
Osmosis
Facilitated diffusion

6. 6.3 Osmosis Diffusion and osmosis are types of passive transport.
Osmosis is the diffusion (movement) of water molecules across a semi permeable membrane.
Can water be toxic to cells?
When might this occur?

7. 6.3 Osmosis Solutions
Diffusion and osmosis are types of passive transport.
There are three types of solutions.
isotonic
hypertonic
hypotonic

8. Osmosis Class Demos Egg Demo Plasmolysis Elodea Leaf lab
What happens to the egg after placement in –
Karyo syrup-
Water-
What did vinegar initially do to the egg?
Are the above solutions hypo, hyper, or isotonic compared to the egg?
Plasmolysis Elodea Leaf lab
What happens to the elodea leaf and its structures when placed in a high salt (hypertonic) solution?

9. Facilitated Diffusion
Some molecules can only diffuse through transport proteins.
Some molecules cannot easily diffuse across the cell membrane.
Facilitated diffusion is diffusion through transport proteins.

10. Facilitated diffusion:
Diffusion of larger molecules through the protein channels in the cell membrane.
Passive transport- no energy needed.
Molecules move from ____ conc. to ____ conc.
Examples include: glucose, water, ions.

11. Selectively Permeable Membrane
Very large molecules will not cross the cell membrane.
Starch Dialysis Bag Demo-
What crossed the dialysis bag?
Starch or Iodine?
Why?

12. Active Transport:
Movement of molecules from______ conc. to ______ conc.
Requires energy (ATP)
Needs transport proteins
Examples- Na/K pump, endocytosis, exocytosis.

13. Transport of Large Molecules:
Vesicles used-
small membrane sacs; move products into, out, or within a cell.
Exocytosis- Materials leave a cell.
vesicle containing the protein fuses with the plasma membrane and spills its contents outside the cell.
Example- release of insulin
Endocytosis-Takes material into the cell.
vesicles bud inward from the plasma membrane
Examples- phagocytosis (solids)