1. Active and Passive TRansport
Cellular Processes
Active and Passive TRansport

2. “Close that window! Do you want to let in all the bugs???
How do you prevent unwanted things from coming through a window?
What part of a cell does the same thing?

3. Moving Cellular Materials
Cells take in food, oxygen and other substances from their environments.
They also release waste materials into their environments.
What organelle works as a gatekeeper to let materials in and out of a cell?

4. Cellular Processes: Active and Passive Transport
Found in both plant and animal cells, the exchange of materials between a cell and its environment takes place in the cell membrane.

5. Small particles cross the cell membrane by way of
Active Transport
And
Passive Transport

6. Active Transport
Active Transport
The movement of substances across the cell membrane that requires using energy by the cell
Endocytosis and Exocytosis
Low concentration to high concentration
Riding a bike up a hill!

7. Endocytosis
The cell membrane surrounds a particle and encloses this particle in a vesicle and brings the particle into the cell
“Into”cytosis
A hug
Endocytosis

8. Exocytosis
The cell membrane encloses a particle in the cell in a vesicle, then moves to the surface, fuses with the cell membrane, and expels the particle.
“Exit”cytosis
Shoving someone

9. Passive Transport
The movement of substances across the cell membrane without using energy by the cell.
Diffusion and Osmosis
High to low concentration
Coasting down a hill on your bike

10. When the molecules are evenly spread, equilibrium occurs.
Diffusion is the movement of particles from areas of high density to areas of lower density.
When the molecules are evenly spread, equilibrium occurs.
To understand how materials move in and out of a cell, you need to know about diffusion….

11. Solids Liquids Gasses Example of a diffusion in a solid:
You put a metal spoon into hot tea or coffee and the entire spoon is hot after a few minutes.
Example of diffusion in a liquid:
Adding a more dense liquid (such as corn syrup) to water
Example of diffusion in a gas:
Someone puts on too much Axe Body Spray after PE. You can smell him before AND after you see him
Diffusion occurs in ….
Solids
Liquids
Gasses

12. Osmosis Osmosis is a special example of diffusion.
It is the diffusion of water through a semi- permeable membrane .
Semi = partial
Permeable= go through, cross
Osmosis

13. Osmosis Osmosis is the process by which water enters our tissues.
All of our cells are surrounded by a membrane that selectively allows anything the cell needs, but prevents unwanted molecules from entering.

14. Water is small enough to get through and enters by diffusion.
This works because the membrane contains lots of tiny holes that will let anything smaller through but obviously will stop big molecules from entering the cell.
Water is small enough to get through and enters by diffusion.
Water will enter until equilibrium is achieved.
How osmosis works

15. EQ: How do cells obtain nutrients to grow and make needed materials?
Acting Out
EQ: How do cells obtain nutrients to grow and make needed materials?

16. Acting Out Active Transport Endocytosis Exocytosis Passive Transport
Diffusion
Osmosis
You probably remember 20-30% of what I taught you yesterday about these processes
20-30% is not enough
I want you to hit at least a 95% understanding

17. Acting Out So what do you need to do to hit that 95%???
Discuss these processes %
What are they?
What are the steps?
What are the expected outcomes you hope to achieve?

18. Acting Out Experience these processes ---85%
As a small group, your table will need to plan and then act out each of these processes:
Endocytosis
Exocytosis
Diffusion
Osmosis
No more than 1 prop per word!
Challenge: act out the words passive transport and active transport

19. Acting Out Attempt to teach ---95%
Be prepared to share at least one of your processes (my choice of course!)
Your acting should be so well-thought out and planned that someone who did not know anything about your process would have an understanding of the process

20. Acting Out 1. Discuss 2. Experience 3. Teach
Endocytosis, Exocytosis, Diffusion, Osmosis
What are they?
What are the steps?
What are the expected outcomes of each process?
2. Experience
Plan how you would teach each process by acting it out
Challenge: Active Transport and Passive Transport
3. Teach
Be prepared to teach any of these processes

22. Osmosis
If cells weren’t surrounded by water that contains few dissolved substances, the water in the cells would diffuse out of them.
Plants=wilting
However, the dissolved substances (solutes), such as salts, sugars, and other substances in the water that surrounds cells, prevent this from happening.
Equilibrium

23. Hypertonic, Hypotonic and Isotonic
A hypertonic solution is a solution(mixture) containing more solute than solvent
A lot of salt (solute) dissolved in water (solvent)
A hypotonic solution is a solution containing more solvent than solute
Purified water --- almost no solute dissolved in the solvent (water)
An isotonic solution is a solution where the solute and solvent are equally distributed.
Cells normally want to remain in an isotonic solution, where the concentration of liquid inside is the same as the concentration of the liquid outside of it.
Equilibrium!