Daily Warm up 9/17/10 H1. What two things must happen for diffusion

to occur?

2. Define these three words: Isotonic solution, Hypotonic, Hypertonic. (where is there more water in each scenario)

3. If your cells were to be placed in salt water what do you think would happen and why?

True and False

1. Only 25% of the world is left handed? 2. Each square inch of human skin

consists of twenty feet of blood vessels.

Daily Warm up 9/23/10 CP•1. Define Osmosis? •2. What happens to a cell that is

hypotonic? •3. What happens to a cell that is

hypertonic? •4. What two things must happen

in order for diffusion to occur?

•5. T/F The average adult has 5 Liters of blood in their body?

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AFTER The warm up:1. Grab your cups and re-measure and weigh

both potatoes. 2. Make one more row on the bottom of your

data sheet and record your info. 3. FINISH ALL the questions and observations in

the lab- INCLUDING the graph. There is graph paper by the printer.

4. Write a paragraph that must include:1. Summary of what you did.

2. What were the conclusions? Did you prove your hypothesis or was it wrong? Why?

3. Were there any problems in the lab that may have messed up your data? (Source of error)

4. What could you have done differently to fix the problems and make the lab more smooth next time.

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Movement through Movement through Cell MembranesCell Membranes-

Gateway to the CellGateway to the Cell

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Cell Membrane controls Cell Membrane controls HomeostasisHomeostasis

• It balances the insideinside and outside of the cell.

•Homeostasis is maintained by plasma membrane controlling what enters & leaves the cell

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Structure of the Structure of the Cell MembraneCell Membrane

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PhospholipidsPhospholipids CholesterolCholesterol Proteins

Carbohydrates (glucose)

Membrane ComponentsMembrane Components

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LABEL THE STRUCTURES

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PhospholipidsPhospholipidsMake up the cell

membrane

Contains 2 fatty acid chains called the tailsContains one glycerol called the head.

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Heads are hydrophilichydrophilic “water loving”Tails are hydrophobichydrophobic “water fearing”

Cell MembraneCell Membrane

Makes membrane “Selective” in what crosses

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Cell MembraneCell MembraneHydrophobic molecules pass easily; hydrophilic DO NOT

The cell membrane is made of 2 layers of phospholipidsphospholipids called the lipid bilayerbilayer

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Small molecules and larger hydrophobic molecules move through easily.e.g. O2, CO2, H2O

Semipermeable Semipermeable MembraneMembrane

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Ions, hydrophilic molecules larger than water, and large molecules such as proteins do not move through the membrane on their own.

Semipermeable Semipermeable MembraneMembrane

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Types of Transport Types of Transport Across Cell Across Cell MembranesMembranes

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Simple DiffusionSimple Diffusion

•Requires NONO energy

•Molecules move from area of HIGH HIGH to LOWto LOW concentration

Diffusion• Two things

need to happen in a cell in order for diffusion to occur… what are they?

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1. Cell membrane must be permeable to that substance.

2. There must be a concentration gradient (needs to be higher in one area and move to lower area)

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DIFFUSIONDIFFUSION

Diffusion is a PASSIVEPASSIVE process which means no energy is used to make the molecules move, they have a natural ENERGY

STOP POINT: • Diffusion of Food Coloring Demonstration.1.EVERYONE Take out a piece of paper (# 1-3). 2.Have someone at your table put in 4 drops of the

food coloring I bring around. 3.Answer these questions- without talking:

1. What happened when the food coloring was added?

2. What did the water look like before the color was added, while it was being added and once it was finished?

3. How did the water end up turning red? (tell me what the molecules were doing).

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Sugar Cube Diffusion• Answer the three questions as you watch

the sugar cube in the next cup of water. 1. What happened when the sugar cube

was added? 2. What did the water look like before

the sugar was added, while it was being added and once it was finished?

3. Explain to me the process of diffusion and how this was an example?

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Diffusion of LiquidsDiffusion of Liquids

Sugar Cube Diffusion

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Diffusion through a Diffusion through a MembraneMembrane

Cell membrane

Solute moves DOWN concentration gradient (HIGH to LOW)

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OsmosisOsmosis• Diffusion of Diffusion of waterwater across a across a

membranemembrane

• Moves from Moves from HIGH water HIGH water potentialpotential (low solute) to (low solute) to LOW LOW water potentialwater potential (high solute) (high solute)

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Diffusion of HDiffusion of H22O Across A O Across A Membrane (Osmosis)Membrane (Osmosis)

High H2O potentialLow solute concentration

Low H2O potentialHigh solute concentration

1. The left side concentration is what?

2.The right side concentration is what?

So which way does water move?

3 Types of Osmosis:

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1.Isotonic Solutions: the solute and water concentration is the same inside the cell as it is outside the cell

2.Hypertonic Solutions: Higher concentration outside the cell than inside the cell.

3.Hypotonic Solutions: Higher concentration inside the cell than outside the cell.

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Cell in Isotonic SolutionCell in Isotonic SolutionWhat is the direction of water movement?

The cell is in _______________.equilibrium

CELLCELL

10% NaCL90% H2O

10% NaCL

90% H2O

ENVIRONMENTENVIRONMENT

NO NET NO NET MOVEMENMOVEMENTT

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Cell in Hypotonic Cell in Hypotonic SolutionSolution

What is the direction of water movement?Water moves into the

cell

CELLCELL

10% NaCL90% H2O

20% NaCL80% H2O

H2O

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Cell in Hypertonic Cell in Hypertonic SolutionSolution

What is the direction of water movement?Water moves out of the

cell.

CELLCELL

15% NaCL85% H2O

5% NaCL95% H2O

ENVIRONMENTENVIRONMENT

H2O

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Cells in SolutionsCells in Solutions

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Isotonic Solution

NO NET MOVEMENT OF

H2O (equal amounts entering

& leaving)

Hypotonic Solution

Water enters cell- can cause it to burst

Hypertonic Solution

Water leaves cell until it “deflates”

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What will happen?What will happen?

How does this relate to Anatomy?

• Discuss at your table this question and appoint someone to share your answer:

• What would happen to your blood cells if the fluid surrounding them had too much salt?

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Osmosis in Red Blood Osmosis in Red Blood CellsCells

IsotonicIsotonic Hypotonic

Hypertonic

What Happens to Blood Cells?

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hypotonic hypertonic isotonic

hypertonic isotonic hypotonic

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STOP POINT:

OSMOSIS ACTIVITY LAB

At your lab tables you are working in groups of 2 or 3. Each lab table should be divided into 2 groups.

WAIT FOR MY DIRECTIONS!

Send one person from your group to the materials table to receive your materials.

WAIT for FURTHER DIRECTIONS.

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3 Types of Transport:

1. Simple Diffusion (also includes osmosis)

2. Facilitated Diffusion

3. Active Transport

Passive Transport vs. Active Transport

• Passive means: it DOES NOT require energy.

• Active means: it DOES require energy.

•Which type(s) are passive? •Which type(s) are active?

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Three Forms of Transport Across the MembraneThree Forms of Transport Across the Membrane

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Passive Passive TransportTransport

Facilitated diffusion

Doesn’t require energy

Uses transport proteins to move high to low concentrationExamplesExamples: : GlucoseGlucose oror amino acidsamino acids moving moving from blood into a from blood into a cell.cell.

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2 Types of Transport 2 Types of Transport ProteinsProteins

• In Facilitated Diffusion- the molecules are too big and need “help” or to be facilitated across.

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Facilitated DiffusionFacilitated Diffusion

copyright cmassengale

1. Channel proteins are embedded in the cell membrane & have a pore for materials to cross

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Facilitated DiffusionFacilitated Diffusion

• They bond and They bond and drag molecules drag molecules through the through the lipid bilayer and lipid bilayer and release them on release them on the opposite the opposite side.side.

2.Carrier proteins can change shape to move material from one side of the membrane to the other

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Carrier ProteinsCarrier Proteins• Carrier proteins Carrier proteins change change

shapeshape to move materials to move materials across the cell membraneacross the cell membrane

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Active TransportActive TransportRequires energy or ATP

Moves materials from LOW to HIGH concentration

AGAINST concentration gradient

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Active transportActive transportExamples: Any Ions:

Pumping Na+ (sodium ions) out and K+ (potassium ions) in.

This happens in your Nervous System!

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Moving the “Big Moving the “Big Stuff”Stuff”Large molecules move materials into the Large molecules move materials into the

cell by one of TWO forms ofcell by one of TWO forms of ENDOCYTOSISENDOCYTOSIS.

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PinocytosisPinocytosis

Sometimes called “Cell Drinking”Sometimes called “Cell Drinking”

Takes in Takes in dissolveddissolved molecules as a molecules as a vesiclevesicle.

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PinocytosisPinocytosis• Called cell Called cell

drinking drinking because once in because once in the cell the cell materials materials dissolve in dissolve in waterwater to be to be used by the cellused by the cell

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Endocytosis – PhagocytosisEndocytosis – Phagocytosis Used to Used to engulf engulf large particleslarge particles such such as as foodfood, , bacteriabacteria, etc. into vesicles, etc. into vesicles

Called Called “Cell Eating”“Cell Eating”

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PhagocytoPhagocytosissis - Capture of a Yeast Cell (yellow) by Membrane Extensions of an Immune System Cell (blue)

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Moving the “Big Stuff”Moving the “Big Stuff”Molecules are Molecules are moved outmoved out of the cell by of the cell by vesiclesvesicles that that fusefuse with the plasma with the plasma membrane.membrane.

ExocytosisExocytosis

This is how many This is how many hormoneshormones are secreted are secreted and how and how nerve cellsnerve cells communicate with one communicate with one anotheranother.

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ExocytosisExocytosisExocytic Exocytic vesicle vesicle immediately immediately after fusion after fusion with plasma with plasma membrane.membrane.

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ExocytosisExocytosis The opposite of endocytosis is exocytosis. The opposite of endocytosis is exocytosis. Large moleculesLarge molecules that are manufactured in that are manufactured in

the cell are the cell are releasedreleased through the cell through the cell membranemembrane..

Inside Cell Cell environment

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How does osmosis or Diffusion play a role in the human body?

What is the main difference between Passive transport and Active transport?

What is endocytosis and exocytosis?

What happens if a red blood cell is in a hypertonic solution? Hypotonic? Isotonic?

REVIEW QUESTIONS