1. Cell Transport Key Points
Molecules do not like being crowded and will move to the less crowded side.
Water will move to the more crowded side.
Active transport takes energy, passive transport does not (ATP).

2. Moving Across a Membrane
Osmosis
Diffusion
Active
What moves
Water
Molecules
Energy No
Yes
Toward which side?
More crowded
Low  high
Less crowded
High  low
Example
Gummy bear swells up in water
Smell of perfume spreading
Sodium-potassium pump

3. CELL TRANSPORT PROBLEM SOLVING STEPS Draw it!
Two areas:
Inside cell
Outside cell
Use dots to represent molecules (stuff)
Find % water and % molecules for both areas (4 numbers in all)
Reread the question – what is moving?
Draw arrows to represent movement.
Answer the question.

4. Example problem
If a kidney cell has a 20% salt solution inside, while the outside of the cell is a 40% salt solution, in which direction will water flow? What will happen to the cell?

5. Survivor island You can have a partner Questions on projector screen
Answer question on your whiteboard
Keep board facedown until Mr. Im says “1, 2, 3, UP!”
If you get the answer correct, stay standing.
If you get the answer incorrect, sit down
You must answer 3 questions correctly before you can stand back up!
Keep track of how many you get right on your whiteboard
Everyone standing at the end gets a prize!

6. In osmosis, what direction does water move?
Question 1
In osmosis, what direction does water move?

7. What is the main difference between diffusion and active transport?
Question 2
What is the main difference between diffusion and active transport?

8. Question 3
If a red blood cell that contains a 30% salt solution is placed in a beaker containing a 5% salt solution, what direction will water flow?

9. What type of transport is this?
Question 4
A cell with 60% salt is placed in a beaker with 80% salt. Salt moves into the cell.
What type of transport is this?

10. Question 8
The following diagram shows which process? A. Passive transport B. Active transport C. Metabolism D. Active osmosis

11. Question 5
A cell with 45% salt is placed in a beaker with 95% salt. Salt moves out of the cell. What type of transport is this?

12. Question 6
A cell with 5% solute concentration is placed in a beaker with a 1% solute concentration. What will happen to the cell over time?
the cell will gain water and expand
the cell will lose water and shrink
the cell will gain and lose equal amounts of water; thus it will remain the same size
the cell will not exchange water with its surroundings

13. Question 16
Choose the cell which would be most likely to experience water flowing in during osmosis. Why did you chose this cell?
A B C

14. Question 7
A cell with 20% sugar concentration is put in a solution with 50% sugar concentration. What would you expect to happen to the cell?
Water moves into the cell and it swells.
Water moves out of the cell and it shrinks.
Water moves out of the cell and it swells.
Equal amounts of water move in and out of the cell and it stays the same size.

15. Question 9 The model below shows what type of transport? Osmosis
Diffusion
Active transport
Facilitated diffusion

16. Question 10
A student notices that the lettuce in a salad wilts (shrivels up) soon after salt is added. Wilting most likely occurs because the lettuce cells:
Absorb extra salt
Release water in the presence of salt
Lose oxygen when in contact with the salt
Gain water in the presence of salt

17. Question 11

18. Question 12
A student places a cell that contains 45% glucose into a solution of 15% glucose. What type of transport is necessary to move glucose out of the cell?

19. Question 13
A person with swollen gums rinses his mouth with warm salt water, and the swelling decreases. What happened?
The swollen gums have absorbed the saltwater solution.
The saltwater solution lowers the temperature of the water in the gums.
The salt in the solution has moved against the concentration gradient.
The water in the gums has moved from a high to a low concentration of water.

20. Question 14
A root cell (part of a plant) with 50% nutrients is placed in soil is 30% nutrients.
Draw diagram that represents this situation.
Draw an arrow representing the movement of water in this cell.
Why does it move this way?

21. Question 15
The diagram below illustrates how plant root cells take in mineral ions from the surrounding soil. What type of transport is this and WHY?

22. Question 17
A cell has a 50% sugar solution. It is in a beaker that has 10% sugar solution. Sugar moves from the beaker to the cell. What type of transport is this?

23. Question 18
A cell is observed to have no sugar inside when it is placed into a concentrated sugar solution. After 10 minutes, there is sugar inside the cell. What type of transport is this?

24. Question 19
A cell that has 5% salt inside the cell is placed into a solution of 2% salt. After 10 minutes, the concentration of salt inside the cell is 7% and the concentration outside the cell is 0%. Fill in the diagram below to figure answer: What type of transport is this?

25. Photosynthesis vs cellular respiration key points
Photosynthesis
Cellular Respiration
WHO?
Plants
Plants and animals 
PRODUCTS?
glucose & oxygen
carbon dioxide + water + ATP energy
WHERE?
Chloroplasts
Mitochondria & cytoplasm
WHY?
Turn sunlight energy into food energy
To turn food energy into ATP energy
EQUATION
Sunlight + 6H2O + 6CO2
 C6H12O6 + 6O2
C6H12O6 + 6O2
 6H2O + 6CO2 + ATP

26. Main point
The products of photosynthesis are the reactants of cellular respiration AND the products of cellular respiration are the reactants of photosynthesis.
Photosynthesis
Cellular Respiration