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Bellwork Wednesday 11/9 *tutorial today for missing work & test makeup 1. What is a phospholipid? 2. How do cell membranes form on their own. Agenda: Finish Notes Q & A worksheet Posters!. Cell Membrane. Forms a barrier around all cells Are made mostly from fats
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Bellwork Wednesday 11/9*tutorial today for missing work & test makeup1. What is a phospholipid?2. How do cell membranes form on their own • Agenda: • Finish Notes • Q & A worksheet • Posters!
Cell Membrane • Forms a barrier around all cells • Are made mostly from fats • They don’t dissolve in water • Are special fats called Phospholipids
- Phospholipids in the cell membrane Form a Lipid Bilayer • - 2 layers back-to-back
Lipid Bilayer is flexible (or fluid) • Cholesterol embedded in membrane • Cholesterol adjusts fluidity • More cholesterol makes membrane stiffer • Less cholesterol makes membrane more liquidy
Transport Proteins • Are like a pore or channel in membrane • Move nutrients in or waste out Transport Protein
100’s of different kinds • Each nutrient needs it’s own • Shape of each Transport Protein fits its nutrient
Fluid Mosaic Model • fluid • lipid bilayer is flexible • Mosaic • Many Transport Proteins embedded in membrane • Looks like a mosaic, sorta
Selective Permeability • Some molecules can pass through • Like nutrients with Transport Proteins • Some molecules can’t pass through • Like many toxins that don’t have Transport Proteins
Cell Membrane Poster20 points, work in pairs Please: Only take a few materials Return everything you don’t use Don’t throw things Clean your workspace Include and LABEL: • Phospholipid • Polar Head • Non-polar Tail • Lipid Bilayer • Transport Proteins • Cholesterol Explain IYOW: (use the question in your answer) • Why polar heads face out • Why nonpolar tails are inside • What transport proteins do • What cholesterol does Use at least one 3D item