Cell Transport
How do materials move into
and out of the cell?
Cell Membrane
•
The cell membrane is like a security
door controlling what materials can
enter and exit the cell.
•
We describe this cell part as:
“selectively permeable.”
•
THINK! - What does selective mean?
• Very Choosy
•
THINK! - What does permeable mean?
• To pass through
Cells Move Materials Using…
NO ENERGY!
Passive Transport
Diffusion
OR
ENERGY!
Active Transport
Osmosis
Today’s Question: What is diffusion?
What is Diffusion?
• You can figure it out by observing 3
examples.
• Example #1: Perfume Demo
• Example #2: Sugar in Water
• Example #3: Food Coloring in Water
Example #1: Perfume Demo
Directions:
1. Your teacher will
spray perfume.
2. Raise your hand
when you can
smell it.
What molecules moved?
Perfume molecules
Did we use energy?
Yes
or
No
In what direction did the
molecules move?
More crowded to less crowded
Less crowded to more crowded
Example #2: Food Coloring
Directions:
1.
2.
3.
Put 1 drop of food coloring
in your beaker of water.
Watch how the molecules
move for 5 minutes.
Sketch your beaker at
start and end.
START
END.
What molecules moved?
Food Dye molecules
Did you use energy?
Yes
or
No
In what direction did the
molecules move?
More crowded to less crowded
Less crowded to more crowded
Example #3: Sugar Cubes
Directions:
1.
2.
3.
4.
Fill your beaker ¼ of the
way up with warm water.
Drop in a sugar cube.
Watch how the molecules
move for 5 minutes.
Sketch your beaker at
start and end.
START
END
What molecules moved?
Sugar molecules
Did you use energy?
Yes
or
No
In what direction did the
molecules move?
More crowded to less crowded
Less crowded to more crowded
What is Diffusion?
Fill in the definition using what you learned.
MOLECULES from
The Movement of ______________
HIGH concentration (more crowded) to
_______
LOW concentration (less crowded) using
_______
______________.
NO ENERGY
EVENLY
The molecules move until they spread out _________.
This is called equilibrium.
WORD BANK
Molecules
No Energy
High
Evenly
Low
Diffusion Animations
• Check out these 2 animations!!
• Perfume Example
http://www.biosci.ohiou.edu/introbioslab/Bios1
70/diffusion/Diffusion.html
• Sugar Cube Example -How Diffusion Works
http://highered.mcgrawhill.com/sites/0072495855/student_view0/chap
ter2/animation__how_diffusion_works.html
• Food Dye Example -Go Animate (Diffusion
runs from start until 2:40)
• http://goanimate4schools.com/public_movie/0Z
Vm9NFo0EC8
C.e.l.l. Solutions ™
Creating Excellent Living Links for the future
Phase 1 –Drug Creation
The Innovation Center is creating a new chemical that will enter
cancer cells. This chemical will kill the cell as it passes through the
cell membrane. The Center is very close to finishing their drug.
However, we need to add one more molecule to make the drug
complete. Which molecule(s) will be small enough to pass
through the cell membrane: Iodine or Starch? Use the principle
of diffusion to figure out the answer.
1.
2.
3.
4.
Build a cell model for diffusion to work.
Fill out the data table.
Analyze data & tell Center which molecule(s) to use.
Call your supervisor over for clearance to clean up.
C.e.l.l. Solutions ™
Creating Excellent Living Links for the future
• Which molecule should the Center use? Why?
The Center should use IODINE because it is small
enough to pass through the membrane. Starch is TOO
big and stayed inside the cell.
Cells Move Materials Using…
NO ENERGY!
Passive Transport
OR
NO ENERGY!
Active Transport
Diffusion Osmosis
Today’s Question: What is osmosis?
C.e.l.l. Solutions ™
Creating Excellent Living Links for the future
Phase 2: Drug Testing on Cell Models
Now that we’ve made our cancer drug we are ready to test it on
animal cells. However, in order for the drug to pass through the
membrane we need cells that are BIG! Which solution will help
our cells grow larger: Freshwater or Saltwater? Please use the
principle of osmosis and soak your gummi cells overnight to
figure out the answer.
1.
2.
3.
4.
5.
Complete Day 1: Set up bears & take measurements
Leave overnight for osmosis to happen.
Complete Day 2: Check bears & take measurements
Analyze data and make a recommendation
Call your supervisor over for clearance to clean up.
C.e.l.l. Solutions ™
Creating Excellent Living Links for the future
• Which solution should the
Innovation Center use:
Freshwater or Saltwater?
Why?
The Center should use
FRESHWATER because
the gummi bear grew
larger.
Osmosis caused the water
to move from HIGH
concentration in the cup
to low concentration
inside the gummi bear.
What is Osmosis?
Fill in the definition using what you learned.
WATER
The Movement of ______________
from
HIGH concentration (more crowded) to
_______
LOW concentration (less crowded) using
_______
______________.
NO ENERGY
EVENLY
The molecules move until they spread out _________.
This is called equilibrium.
WORD BANK
Water
No Energy
High
Evenly
Low
Osmosis Problems
• Problem #1 – A cell is placed in pure Freshwater.
Which way will the water flow?
CELL SWELLS
Osmosis Problems
• Problem #2 – A cell is placed in saltwater. Which
way will the water flow?
Salt molecule
CELL SHRINKS
Osmosis Problems
• Problem #3 – A cell is already at equilibrium.
Which way will water flow?
SAME SHAPE
Osmosis
Animations
• Animation #1 http://www.stephsnature.com/lifescience/osmosisanimations.
htm
• Animation #2http://www.stolaf.edu/people/giannini/flashanimat/transport/os
mosis.swf
• Animation #3-Go Animate (Osmosis runs from 2:40 until end)
http://goanimate4schools.com/public_movie/0ZVm9NFo0EC8
Activity: Osmosis in Animal Cells
How would you explain this cartoon using your
knowledge of osmosis?
My Answer:
Slugs are afraid because
salt will make their cells
shrink.
Low
High
The water will move from
HIGH conc. (inside cell)
to LOW conc. (outside cell).
Activity: Osmosis in Plant Cells
• What happens when plant
cells are in freshwater?
Water moves
into cell
• What happens when plant cells
are in saltwater?
Water Leaves
the cell
C.e.l.l. Solutions ™
Creating Excellent Living Links for the future
Phase 3: Drug Delivery
You have already completed two phases of this project. In this
last phase we must deliver the drug inside the cell.
Unfortunately, with all the extra modifications that we did, the
drug turned out to be TOO BIG to pas through the membrane.
How can we get LARGE molecules to enter the cell? Please
use the idea of active transport to model a way that the cell can
do this using materials provided.
1.
2.
3.
4.
Read instructions
Use materials and model a method
Share your solution
Call your supervisor over for clearance to clean up.
C.e.l.l. Solutions ™
Creating Excellent Living Links for the future
•
The Question:
•
•
The Task:
•
•
How can we get LARGE molecules to enter the cell?
For this task gather the following materials to work with.
• 1 plastic shopping bag
• 1 pair of scissors
• ~ 15 cm of string
• 1 small wrapped candy
Rules:
•
•
•
•
1. The candy must enter through the solid part of the bag.
2. The inside of the bag can NOT be open to the outside.
3. The candies entering the bag must remain clustered together.
4. You many work with your hands inside the bag.
What is your solution?
Cells Move Materials Using…
NO ENERGY!
ENERGY!
Passive Transport
Active Transport
Diffusion
Osmosis
Today’s Question: What is active transport?
Active Transport
• The movement of Large
particles across the cell
membrane
• The cell uses ENERGY
• Active Transport is like
pedaling a bike uphill.
Molecules move from LOW
concentration to HIGH
Concentration.
Engulfing
• One type of active transport is called engulfing.
• The cell membrane wraps around the large
particle.
• It is then brought into the cell as a vesicle.
Englufing Animations (also called endocytosis)
http://www.youtube.com/watch?v=4gLtk8Yc1Zc (Narrated)
http://www.stolaf.edu/people/giannini/flashanimat/cellstructure
s/phagocitosis.swf
http://www.maxanim.com/physiology/Endocytosis%20and%20E
xocytosis/Endocytosis%20and%20Exocytosis.htm