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Cell membrane

Cell membrane. How is the environment connected to the Cells?. Video. Review: Remember Chemistry. What does polar mean? Polar means a molecule has a positive and negative end. How do polar molecules behave? (“like dissolves like”) Polar molecules attract to other polar molecules

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Cell membrane

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  1. Cell membrane

  2. How is the environment connected to the Cells? Video

  3. Review: Remember Chemistry What does polar mean? • Polar means a molecule has a positive and negative end • How do polar molecules behave? • (“like dissolves like”) Polar molecules attract to other polar molecules • Polar molecules do not attract nonpolar molecules.

  4. Basic Structure • What do you need to know? • Phospholipids • arranged in a double layer called a bilayer. • Phospholipids are polar molecules. • Positive (hydrophilic = water loving) : head • Negative (hydrophobic = water hating) : tail

  5. Cell Function What do cells need to get in and out to function properly? • Molecules: • CO2 (Carbon Dioxide) = Nonpolar, small molecule • O2 (Oxygen) = Nonpolar, small molecule • H2O (Water) = Polar, small molecule • C6H12O6 (sugars/glucose) = Nonpolar, large molecules • Amino Acids (building block of proteins) = typically Nonpolar, large molecules • Nucleic Acids (building blocks of DNA) = typically Nonpolar, large molecule • Lipids (Called fatty acids) = typically Nonpolar, large molecule • Ions = Charged molecules that need to get into or out of the cell

  6. Jig-saw: Cell Membrane Function 6 ways molecules move 1. Diffusion (p. 74-75) 2. Osmosis (p. 76-77) 3. Facilitated Diffusion (p. 80) 4. Sodium-Potassium Pump (p. 81-82) 5. Endo- & Exocytosis (p. 83) 6. Membrane Receptor Proteins (p. 84-86) Assignment: • Class number off 1 through 6. • ID specific responsibilities based on your number. • Read the text • Take notes on what is the important must knows.

  7. Jig-saw: Cell Membrane Function 6 ways molecules move 1. Diffusion (p. 74-75) 2. Osmosis (p. 76-77) 3. Facilitated Diffusion (p. 80) 4. Sodium-Potassium Pump (p. 81-82) 5. Endo- & Exocytosis (p. 83) 6. Membrane Receptor Proteins (p. 84-86) Assignment: • Get in to groups based on your assigned number. Discuss the must knows from the reading. • Each member draw a picture expressing the must knows. “No Words” • Plus discuss a real world application of this process.

  8. Jig-saw: Cell Membrane Function 6 ways molecules move 1. Diffusion (p. 74-75) 2. Osmosis (p. 76-77) 3. Facilitated Diffusion (p. 80) 4. Sodium-Potassium Pump (p. 81-82) 5. Endo- & Exocytosis (p. 83) 6. Membrane Receptor Proteins (p. 84-86) Assignment: • Get into groups with people of your non number. We are going to go with 5 groups. • Teacher/student • Each person is responsible for teaching their part. • Everyone is taking notes and copying the illustration.

  9. Lab Obtain… 2 sandwich bags 2 plastic cups 2 rubber bands Experiment 1 • Fill sandwich bag with 20 mL of Iodine rap rubber band around opening • Fill plastic cup w/ 20 mL of Starch solution. • Place bag in beaker so opening is outside the beaker • Let stand until next class Experiment 2 • Fill sandwich bag with 20 mL of Starch solution rap rubber band around opening • Fill plastic cup w/ 20 mL of Iodine. • Place bag in beaker so opening is outside the beaker • Let stand until next class

  10. Iodine/Starch Lab Observations • Draw a picture of the before and after for each experiment. • Write a TELL-Con about the experiment. • Answer the questions has evidence. • Do both molecules move through the bag? • What is it about the structure of a each molecule that determine whether of not it move through the bag? • I2 • Starch = Several glucose (C6H12O6) molecules attached to one another • What molecule(s) moves into the bag and why?

  11. What are the keys to getting across the cell membrane? • Size • Polarity • Concentration

  12. Vocabulary that is good to know • Solution • Solute (sugars or salts) • Solvent (water) • Concentration Gradient • If there is a lot of solute = high concentration • If there is little solute = low concentation • If you move with the concentration gradient High  Low • If you move against the concentration gradient Low  High • When the concentrations are equal we call that equalibrium.

  13. Passive v. Active Transport • Passive Transport • No energy needed • Moves with the concentration gradient • Active Transport • Requires energy • Moves against concentration gradient

  14. Let’s start with Nonpolar, Small molecules Diffusion • Passive Transport • Movement of molecules from a high concentration to a low concentration. • Ex. A Fart! • With the cell membrane diffusion occurs through phospholipids

  15. Let’s talk about water(Nonpolar, small molecules) Osmosis • Passive Transport • Movement of water from a high concentration to a low concentration. • Ex. Bounty paper towel • Water move through the phospholipids

  16. Terms to know about Osmosis • Hypotonic • The lower concentration of solute • Hypertonic • The high concentration of solute • Isotonic • Concentration of solute is equal on both sides Link to Animation http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html

  17. Write TELL-Con on Egg Demo • Use the information learned over the past two slides to answer what happens in the Egg Demo.

  18. Let’s talk about Large molecules moving with concentration gradient Facilitated Diffusion • Passive Transport • Because it is a large molecule it will need an opening to get through. A carrier protein. Link to Animation http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_facilitated_diffusion_works.html

  19. Ion Channel Transport Ions (charged molecule) • Passive Transport • Special channel needed to get charged molecules into and out of the cell with the concentration gradient Click Here for Animation

  20. Let’s talk about movement against the concentration gradient. • Active Transport • Needs Energy • Need to know the sodium/potassium Link to Animation http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/animations/ion_pump/ionpump.html

  21. Receptors Proteins Click here for video Form of active transport

  22. Endo- and Exocytosis Passive transport • Endo- = “in” • Exo- = “out” • cyto- = “cell” • -osis = “process” What is Endocytosis? What is Exocytosis? Click here for animation http://www.maxanim.com/physiology/Endocytosis%20and%20Exocytosis/Endocytosis%20and%20Exocytosis.htm

  23. Cell Transport Click here for the video!

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