1. Passive Transport A.K.A. THE LAZY ONE THAT DOESN’T NEED ENERGY
Przeworski

2. Homeostasis https://www.youtube.com/watch?v=9RLnlXNlfdk
Why do we want to keep a constant internal environment?
Temperature pH
Salt/Potassium/Ion content

3. In passive transport:
Molecules always move across the cell membrane without the use of energy
Molecules always move from high to low concentration (from where there are more to where there are fewer)
Low
High
High
Low
ATP

4. Diffusion Diffusion is the most basic form of passive transport
Occurs everywhere, not just across membranes
Equilibrium is reached when diffusion has caused molecules to spread out evenly

5. Facilitated Diffusion
In facilitated diffusion, molecules move through the membrane with help from proteins
Channel proteins are open doors
Carrier proteins open and close
Channel
Carrier

7. Osmosis In Osmosis, water molecules diffuse through a membrane
Solute: a substance dissolved in a liquid
Solvent: liquid that dissolves the solute
Solution: mixture of solute and solvent

8. Osmosis Tonicity describes relative concentrations of solute:
Hypertonic: Concentration is higher relative to something else
Hypotonic: Concentration is lower relative to something else
Isotonic: Both concentrations are equal

9. In which beaker would we expect to see the greatest movement of particles? (list the percents as your answer)

11. Which direction will the water move?
The Plasma Membrane
1/28/2018
Cell in Hypertonic Solution
15% Solute 85% H2O
CELL
5% Solute
95% H2O
Which direction will the water move?
G. Podgorski, Biol. 1010

12. Which direction will the water move?
The Plasma Membrane
1/28/2018
Cell in Hypotonic Solution
20% Solute 80% H2O
CELL
30% Solute
70% H2O
Which direction will the water move?
G. Podgorski, Biol. 1010

13. Which direction will the water move?
The Plasma Membrane
1/28/2018
Cell in Isotonic Solution
10% Solute 90% H2O
CELL
10% Solute
90% H2O
Which direction will the water move?
G. Podgorski, Biol. 1010

14. What happens when plant cells are placed in solutions of different tonicity?
Plasmolyzed: Water leaves plant cells, causes the cell membrane to pull away from the cell wall (plasmolysis), plant wilts
Turgid: Water moves into plant cells, makes cells plump, plant remains rigid

15. Video-BIo https://www.youtube.com/watch?v=IaZ8MtF3C6M
Video: Pre-AP (first 5 minutes)

16. Exit ticket:
A student measures the mass of each of six potato cores and places one core in each of six different unknown solutions. After a period of time, the student removes the potato cores and measures the mass of each one.
Solution
Potato Core Mass 1
Increase 2
Decrease 3
No Change 4 5 6
Which two potato cores were placed in an isotonic solution?

17. In groups of 2-3
You will be responsible for a poster of one of these types of transport:
Diffusion, Osmosis, Facilitated Diffusion or Hypertonic/Hypotonic/Isotonic
Include a picture/diagram of how it works
If it needs ATP or not (active or passive)
A short summary (2-3 sentences) about how it works

18. Presentations- 2 minute style
Every person says something
You may read directly off your poster
Go slowly.
Answer questions
Applaud for your classmates when they finish!