Tonicity is a measure of the osmotic pressure (as defined by the water potential of the two solutions) of two solutions separated by a semipermeable membrane.

Cells can be placed in solutions that have the same percentage of solute, a higher percentage of solute, or a lower percentage of solute than the cell. (You’ll need to pieces of paper today) On your own sheet of note book paper, draw the following chart (front page) to refer back to when constructing your story board.

Tonicity of Solution Concentration of Solute (outside of cell) WaterNet Movement Effect IsotonicSame as cell None Hypotonic Less than cell More than cell Cell gains water Swells, turgor pressure Hypertonic More than cell Less than cell Cell loses water Shrinks plasmoly sis

On the back of your paper you will be constructing two story boards. Step 1: fold your paper in half hot dog style and draw a line down the middle. Step 2: in the top half, draw three rectangles like this. (Repeat this step in bottom half.)

 The first rectangle will be titled “Cell in a Hypertonic Solution”  Draw a red blood cell in your rectangle floating in a solution labeled hypertonic.  The middle rectangle will be titled “Water movement”  Draw the red blood cell floating in a solution with arrows pointing in the direction of water movement.  The third rectangle will be titled “Effect on the Cell”  Draw the red blood cell after it has been affected by the hypertonic solution.

 The first rectangle will be titled “Cell in a Hypotonic Solution”  Draw a red blood cell in your rectangle floating in a solution labeled hypotonic.  The middle rectangle will be titled “Water movement”  Draw the red blood cell floating in a solution with arrows pointing in the direction of water movement.  The third rectangle will be titled “Effect on the Cell”  Draw the red blood cell after it has been affected by the hypotonic solution.

 On a second sheet of paper, draw a triple Venn diagram using up the whole page. Make sure your three circles over lap in the middle so you can write what all three have in common: Passive Transport.

Diffusion Osmosis Facilitated Diffusion

 Compare and contrast the three topics in the Venn diagram using these phrases:  Passive transport: movement of molecules across a membrane along concentration gradient.  Movement of small molecules.  Movement of molecules. (Goes in three parts of the diagram)  Movement of water molecules.  Proteins facilitating the movement of large molecules.

 All three: Passive transport: movement of molecules across a membrane along concentration gradient.  Diffusion: movement of small molecules.  Diffusion and osmosis: Movement of molecules.  Osmosis: movement of water molecules.  Osmosis and facilitated diffusion: movement of molecules.  Facilitated diffusion: Proteins facilitating the movement of large molecules.  Facilitated diffusion and diffusion: movement of molecules.

 On the back of your 2 nd sheet of paper, draw a line across the top blue line of your paper and a line down the middle of the page.  Title one side Passive Transport and the other side Active transport.  Determine which phrases on the next slide go under passive or active.

 Requires energy to move molecules against their concentration gradient  Osmosis: movement of water molecules across a membrane.  Facilitated diffusion: Proteins help molecules move across the membrane along their concentration gradient  Exocytosis: Movement of large molecules out of the cell  Diffusion: particles moving across a membrane along their concentration gradient  Does not require energy to move molecules against their concentration gradient.  Endocytosis: movement of large molecules into the cell  Protein Pumps: use energy to pump molecules across a membrane against their concentration gradient.

 Passive  Does not require energy to move molecules against their concentration gradient.  Diffusion: particles moving across a membrane along their concentration gradient  Osmosis: movement of water molecules across a membrane.  Facilitated diffusion: Proteins help molecules move across the membrane along their concentration gradient  Active  Requires energy to move molecules against their concentration gradient  Endocytosis: movement of large molecules into the cell  Protein Pumps: use energy to pump molecules across a membrane against their concentration gradient.  Exocytosis: Movement of large molecules out of the cell

 Now you have 4 great graphic organizers to keep in your binder to help you study for your cell test on Tuesday, November 2!