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…

ORActive TransportPassive Transport

ENERGY!

Diffusion Osmosis

NO ENERGY!

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.

Did we use energy?Yes or No

What molecules moved?

In what direction did the molecules move?More crowded to less crowded

Less crowded to more crowded

Perfume molecules

Example #2: Food Coloring

Directions:1. Put 1 drop of food

coloring in your beaker of water.

2. Watch how the molecules move for 5 minutes.

3. Sketch your beaker at start and end.

START END.

What molecules moved?

Did you use energy?Yes or No

In what direction did the molecules move?More crowded to less crowded

Less crowded to more crowded

Food Dye molecules

Example #3: Sugar CubesDirections:

1. Fill your beaker ¼ of the way up with warm water.

2. Drop in a sugar cube.3. Watch how the

molecules move for 5 minutes.

4. Sketch your beaker at start and end.

START END

What molecules moved?

Did you use energy?Yes or No

In what direction did the molecules move?More crowded to less crowded

Less crowded to more crowded

Sugar molecules

What is Diffusion? Fill in the definition using what you learned.

The Movement of ______________ from _______ concentration (more crowded) to _______ concentration (less crowded) using ______________. The molecules move until they spread out _________. This is called equilibrium.

WORD BANK

Molecules No Energy High Evenly Low

MOLECULESHIGH

LOWNO ENERGY

EVENLY

Diffusion Animations• Check out these 2 animations!!

• Perfume Example http://www.biosci.ohiou.edu/introbioslab/Bios170/diffusion/Diffusion.html

• Sugar Cube Example -How Diffusion Works http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html

• Food Dye Example -Go Animate (Diffusion runs from start until 2:40)

• http://goanimate4schools.com/public_movie/0ZVm9NFo0EC8

Phase 1 –Drug CreationThe 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. Build a cell model for diffusion to work.2. Fill out the data table.3. Analyze data & tell Center which molecule(s) to use.4. Call your supervisor over for clearance to clean up.

C.e.l .l . Sol ut ions ™ Creating Excellent Living Links for the future

• Which molecule should the Center use? Why?

C.e.l .l . Sol ut ions ™ Creating Excellent Living Links for the future

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! OR NO ENERGY!

Passive Transport Active Transport

Diffusion Osmosis

Today’s Question: What is osmosis?

C.e.l .l . Sol ut ions ™ Creating Excellent Living Links for the future

Phase 2: Drug Testing on Cell ModelsNow 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. Complete Day 1: Set up bears & take measurements2. Leave overnight for osmosis to happen.3. Complete Day 2: Check bears & take measurements4. Analyze data and make a recommendation 5. Call your supervisor over for clearance to clean up.

• Which solution should the Innovation Center use: Freshwater or Saltwater? Why?

C.e.l .l . Sol ut ions ™ Creating Excellent Living Links for the future

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.

The Movement of ______________ from _______ concentration (more crowded) to _______ concentration (less crowded) using ______________. The molecules move until they spread out _________. This is called equilibrium.

WORD BANK

Water No Energy High Evenly Low

WATER

HIGHLOW

NO ENERGY

EVENLY

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?

CELL SHRINKS

Salt molecule

Osmosis Problems• Problem #3 – A cell is already at

equilibrium. Which way will water flow?

SAME SHAPE

OsmosisAnimations

• Animation #1 - http://www.stephsnature.com/lifescience/osmosisanimations.htm

• Animation #2-

http://www.stolaf.edu/people/giannini/flashanimat/transport/osmosis.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 becausesalt will make their cells shrink.

The water will move from HIGH conc. (inside cell)to LOW conc. (outside cell).

High

Low

• What happens when plant cells are in freshwater?

Water moves into cell

Water Leavesthe cell

• What happens when plant cells are in saltwater?

Activity: Osmosis in Plant Cells

C.e.l .l . Sol ut ions ™ Creating Excellent Living Links for the future

Phase 3: Drug DeliveryYou 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. Read instructions2. Use materials and model a method3. Share your solution4. Call your supervisor over for clearance to clean up.

C.e.l .l . Sol ut ions ™ Creating Excellent Living Links for the future

• The Question: • How can we get LARGE molecules to enter the cell?

• The Task: • 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?

Passive Transport

ENERGY!

Diffusion Osmosis

NO ENERGY!

Cells Move Materials Using…

Active Transport

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.

• 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/cellstructures/phagocitosis.swf

http://www.maxanim.com/physiology/Endocytosis%20and%20Exocytosis/Endocytosis%20and%20Exocytosis.htm

Engulfing