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The Semipermeable Membrane: Phospholipid Bilayer. Monday November 22, 2010. In your Notebook. Remember: Water is a polar molecule. Like Attracts Like. Warmup. Pass in Lab Reports Watch the demonstration. 1. Explain how water is interacting with the magic sand and clear spheres.
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The Semipermeable Membrane:Phospholipid Bilayer Monday November 22, 2010
In your Notebook Remember: Water is a polar molecule. Like Attracts Like
Warmup • Pass in Lab Reports • Watch the demonstration. • 1. Explain how water is interacting with the magic sand and clear spheres. • 2. What does this tell you about the properties of these substances.
Heads and Tails of the Phospholipid Bilayer http://telstar.ote.cmu.edu/biology/MembranePage/index2.html
Passive Transport Does Not Require ENERGY… Substances flow down the Concentration Gradient. • We’ve seen: • Water • Glucose • Iodine
Active Transport Requires Energy to Move Molecules across the Membrane
Now: Let’s Model the Phospholipid Bilayer • Follow the directions on your worksheet. • Answer all questions. • Work in pairs; Each person must complete his/her own worksheet.
75% H20 25% NaCl 40% H20 60% NaCl Quiz Feedback • Question #1: • Some common misunderstandings- • NaCl can pass through membrane • NaCl soaks up the water • The cell will actually swell • Hypotonic Solution • Question #2: • Looking for a basic definition of selective permeability and an example… • What were some examples in class?? • #3: Think back to question #1, and the elodea lab • #4: Proteins can’t get re-absorbed (why?). • Glucose is mostly re-absorbed (why?)
Homework • Read BSCS Membranes Essay p. 220-221. • Complete reading guide questions in Notebook.