1. Cellular Transport A journey that will take you places

2. Diffusion Solutions are homogeneous mixtures comprised of Solutes dissolved in Solvents. For example, a solution of sugar water consists of sugar (the solute) dissolved in water (the solvent)

3. 4 examples of Salt added to water 10g of salt, 300ml H 2 O 20g of salt, 300ml H 2 O 30g of salt, 300ml H 2 O 40g of salt, 300ml H 2 O AB C D In your notes, answer the following questions: 1) What is the solvent? 2) What is the solute? 3) Which glass has the greatest solute concentration? 4) How many ml of H 2 O would you need to add to 60g of Salt to have the same solute concentration as glass C?

4. 10g of salt, 300ml H 2 O 20g of salt, 300ml H 2 O 30g of salt, 300ml H 2 O 40g of salt, 300ml H 2 O ? ? ?

5. Individual molecules move randomly and unpredictably

6. However, overall movements of many molecules can be predicted. Guess the positions of the molecules in this box after 10 min. 10 min ?

7. This movement is known as diffusion Diffusion: The net movement of molecules from areas of high concentration to areas of low concentration

8. Dissolved solutes can diffuse across the cell membrane by moving down their concentration gradient (High concentration to Low concentration). This DOES NOT require cellular energy

9. Make a model of Diffusion! Using the materials at your table, show the diffusion of a solute across a phospholipid bilayer. You should include: – A before, where one side has high solute concentration and the other side has low solute concentration – An after, where both sides have equal solute concentration Sketch the before and after and show the solute movement in your notes.

10. Osmosis Osmosis is a specific type of diffusion. It is the diffusion of water across a semipermeable membrane. Osmosis: the movement of water down its concentration gradient – through a selectively permeable membrane from a region of lower solute concentration to a region of higher solute concentration.

11. Tonicity Tonicity: the relative concentrations of solutes in two fluids separated by a selectively permeable membrane. The fluid with lower solute concentration is hypotonic, and the one with higher solute concentration is hypertonic. Water always diffuses from hypotonic to hypertonic. Isotonic fluids have the same solute concentration on both sides of a membrane.

12. This is a light microscope image of the cells in an Elodea leaf. Predict what will happen if this leaf is submerged in a hypertonic solution. Make a before and after sketch in your lab notes.

13. Which solution is hypotonic? Hypertonic? Isotonic? Isotonic HypertonicHypotonic

14. Make a model of Osmosis! Using the materials at your table, show osmosis across a phospholipid bilayer. You should include: – A before, where one side is hypertonic and the other side is hypotonic – An after, where both sides are isotonic Sketch the before and after and show the water movement in your notes.

15. Overview of Diffusion and Osmosis

16. Passive and Active Transport Molecules that cannot pass through the membrane (too large, too polar) are transported through by membrane proteins. There are two main kinds of transport: passive transport and active transport Passive transport: Doesn’t require ATP energy Active transport: requires ATP energy

18. Passive Transport Solute moves from high concentration to low concentration through a passive protein transporter Does not require energy The membrane protein is basically a tunnel that allows large or polar molecules to diffuse across the membrane when they would ordinarily be blocked

19. Make a model of passive transport! Using the materials at your table, show the passive transport of a solute across a phospholipid bilayer. You should include: – A before, where one side has high solute concentration and the other side has low solute concentration – An after, where both sides have equal solute concentration Sketch the before and after and show the solute movement in your notes.

20. Active Transport Solute moves from low concentration to high concentration through an active protein transporter REQUIRES ENERGY The membrane protein is basically an airlock that uses energy to transport molecules against their concentration gradient

21. Make a model of active transport! Using the materials at your table, show the active transport of a solute across a phospholipid bilayer. You should include: – A before, where one side has high solute concentration and the other side has low solute concentration – An after, where on side has an even high solute concentration and the other side has an even lower solute concentration – Show that ATP is used! Sketch the before and after and show the solute movement in your notes.

22. Overview of Passive and Active Transport

23. Endocytosis and Exocytosis Sometimes molecules are far too large for transport proteins to help across membranes Endocytosis  Exocytosis 

24. Make a model of endocytosis and exocytosis! Using the materials at your table, show endocytosis and exocytosis across a phospholipid bilayer. You should include: – A before, where the vesicle is just beginning to form around the molecules – A middle, where the vesicle is mostly formed around the molecules – An after, where the vesicle is fully formed and on the other side of the membrane Sketch the before middle and after and show the molecule movement in your notes.

25. Phagocytosis : awesome endocytosis Phagocytosis is a form of endocytosis where a cell eats something else whole. This is awesome This is also one way your white blood cells capture and kill pathogens. The coolest video ever

26. Overview of Endocytosis and Exocytosis

27. Overview of overviews