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CELL TRANSPORT

CELL TRANSPORT. Define these terms:. 1. Solute * 2. Solvent * 3. Semipermeable Membrane* 4. Passive Transport* 5.Active Transport* 6. Diffusion* 7. Osmosis* 8. Concentration Gradient 9. Facilitated Diffusion 10. Hypertonic 11. Hypotonic 12. Isotonic .

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CELL TRANSPORT

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  1. CELL TRANSPORT

  2. Define these terms: 1. Solute * 2. Solvent * 3. Semipermeable Membrane* 4. Passive Transport* 5.Active Transport* 6. Diffusion* 7. Osmosis* 8. Concentration Gradient 9. Facilitated Diffusion 10. Hypertonic 11. Hypotonic 12. Isotonic

  3. Research the Following

  4. How do molecules get into the cell? • By crossing the Cell Membrane!

  5. What is a key property of the Cell Membrane? • Selective Permeability!! • This property of biological membranes allows some substances to cross more easily than others.

  6. How much energy will it cost the cell to MOVE molecules in or out? • It depends on HOW it enters the cell! • Which do you think does NOT “cost” the cell energy- Passive Transport or ActiveTransport? PASSIVE TRANSPORT

  7. First type Passive Transport-Diffusion • What is it? • Random movement of moleculesdown a concentrationgradientfrom an area of highconcentrationto an area of lowconcentration. • NOenergy is expended.

  8. Diffusion

  9. Watch this animation! • http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html • http://www.indiana.edu/~phys215/lecture/lecnotes/diff.html

  10. 2nd type Passive Transport-Osmosis • The diffusion of water across selectively permeable membranes. • Watermoves from a high water concentrationto low water concentration. • NO energy expended by cell

  11. 3nd type passive transportFacilitatedDiffusion Type which uses transport proteinsto move molecules across the membrane WITHOUT any energy expended by cell!

  12. Question:What’s in a Solution? Answer: • solute + solventsolution • NaCl + H20saltwater

  13. solution 3% NaCl 5% NaCl 97% H2O 95% H2O Red Blood Cell Hypertonic • A solution with greater solute concentration (less water) compared to another solution.

  14. 3% Na solution 97% H2O 1% Na 99% H2O Red Blood Cell Hypotonic • A solution with lower solute concentration (more water) compared to another solution.

  15. solution 3% Na 97% H2O 3% Na 97% H2O Red Blood Cell Isotonic • A solution with an equal solute concentrationcompared to another solution. • This solution is said to be in equilibrium.

  16. Movement of H2O = OSMOSIS! • Water will “ALWAYS”diffuse down a concentration gradient from a HYPOTONICsolution(more water, less solute) to a HYPERTONICsolution (less water, more solute). ALWAYS REMEMBER- water moves from • HYPOTONIC HYPERTONIC

  17. Red Blood Cell Animal Cells • Animal cells placed into a hypotonic solution will EXPLODE. Hypotonic

  18. Red Blood Cell Animal Cells • Animal cells placed into a hypertonic solutionwill SHRIVEL. Hypertonic

  19. Water Water Central Vacuole Cell Wall Water Plant Cells • In a hypotonic environment, the vacuole is full of water (cell gains water), and the cell membrane is pushed against the cell wall. The cell wall helps the plant cell retain its shape under the tension.

  20. Water Water plasma membrane Cell Wall Water Plant Cells • In a hypertonic environment(loss of water), the plasma membrane pulls away from the cell wall(vacuole empty).

  21. Active Transport • The movement of molecules(small or large) across the plasma membrane using energy (ATP).

  22. Examples of Active Transport: Active transport using a carrier molecule in the membrane - many times, this involves moving molecules from a low to high concentration (OPPOSITE the direction during diffusion!). - Requires ATP (ENERGY!!) to move it across!

  23. Protein pumps • Some membrane proteins use energy to pump substances in and out of the cell. • Sodium potassium pump animation.

  24. How are large molecules transported into and out of the cell? • Endocytosis and Exocytosis (BOTH are active transport!)

  25. Endocytosis • ENTRY into cell • Portion of the membrane surrounds or engulfs a macromolecule (large molecule) outside cell. The membrane pinches off to form a vesicle in the cytoplasm • Requires Energy!!

  26. Endocytosis, cont. Different names for type macromolecules endocytosed: • Pinocytosis: endocytosis of liquids • Phagocytosis: endocytosis of particles • http://www.stolaf.edu/people/giannini/flashanimat/cellstructures/phagocitosis.swf

  27. Endocytosis, cont. • Amoeba feeding

  28. Exocytosis: • EXPORT of materials OUT of the cell (wastes, cell products) - Also a type of Active Transport (energy required!!)

  29. Quick Quiz • 1. Which type of transport REQUIRES energy? • 2. Which type of transport does NOT require energy? • 3. In a Hypertonic solution, the amount of solute is _________ in the solution than the solute concentration inside the cell. • 4. In an Isotonic solution, the amount of solute is __________ the solute concentration inside the cell.

  30. Quick Quiz, cont. • 5. Movement of macromolecules OUT of the cell is called __________. Does this require energy? • 6. Endocytosis that involves movement of liquids into the cell is called ______________. Does this require energy?

  31. Plastic baggies are a lot like cell membranes; they are semipermeable. Do baggies allow any of the following - water, starch, or iodine - to move through them? Materials: baggies Starch suspension in H2O Iodine solution Beakers MODELLING A CELL MEMBRANE

  32. DO Now! • Sheet 3.5 • Complete and we will discuss it

  33. Concentration ProblemsIn each problem below, the membrane is permeable to water only! 1.Which way will water move – into or out of the body cell? (draw an arrow!) 2. The solution is ________.

  34. 3. Which way will water move – into or out of the sphere? (draw an arrow!) 4. Is the solution in the beaker hypotonic, isotonic, or hypertonic compared to the cell? (Circle one!)

  35. 5. Which way will water move – into or out of the sphere? (draw an arrow!) 6. What will happen to the shape / size of the sphere? What is the solution outside the cell?

  36. 7. Which way will water move – into or out of the body cell? (draw an arrow!) Cell 0.45 M solute 0.35 M solute 8. What is the cell’s solute concentration after dynamic equilibrium is reached?

  37. 9. Which way will water move – into or out of the body cell? (draw an arrow!) cell 10. What is the cell’s water concentration after dynamic equilibrium is reached?

  38. Wrap up of Transport across a Semipermeable membrane! • BEFORE you get your beaker, write down what you EXPECTED to happen? (Who moved across the plastic membrane?)

  39. How did your experiment work? • Did the liquid in the beaker or the baggie change color? What does it indicate? • Decide WHICH molecules were transported- water, iodine, or starch? • Did your experiment test all 3 components?

  40. Cont…. • Things to think about: • Size of atoms/ molecules • Set-up of experiment- could you detect movement of ALL molecules? • Validity/ reliability • How is the baggy LIKE a cell membrane? • How is it NOT LIKE a cell membrane?

  41. Wrap-up! • Standard 10.1: FUNDAMENTAL life processes depend on the physical and chemical activities of the cell. • D30. Explain the role of the cell membrane in supporting cell functions. • What ARE the roles of the cell membrane?

  42. Wrap-up! How is the cell membrane structured to ensure efficiency and survival?

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