Biological Membranes

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Biological Membranes
Lipids define space, provide barrier, act as
label
Membrane Proteins
What functions would require the different
categories of membrane proteins?
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Cells are stable
And yet they respond and move
How?
Ch15 video Chemotaxis of a Single Dictyostelium
Cell
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Fluid Mosaic Model (revised)
1. Length and saturation of fatty acid chains in
phospholipids
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More model
2. Amount of Cholesterol (and cholesterol paradox)
3. Temperature
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More model 2
If everything can move is everything randomly
distributed?
Lipid rafts Tethering Complex formation
Why is this level of organization important for
correct cellular function?
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Questions?
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Membranes define organelles.How?
Cell City
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Coordinating the parts and the whole
Overcoming the barrier ? ways to cross
a membrane gated transport
transmembrane transport vesicular transport

• ways to signal without crossing
• receptors and conformational change

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Case Study 1
What else?
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Graves opthalmopathy
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Pretibial dermopathy
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Goiter
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History
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Cause?
Unknown
Players?
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Why use this case study?
Compare what should happen with What actually
occurs
Focus on Extracellular signaling Intracellular
signaling Protein structure and function
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This week in Cell Bio
Lab Getting a feeling for the organism Mating
vs budding yeast what can you tell? Designing
experiments to distinguish between types of
extracellular signaling microscopy/
plating experimental design Class
Extracellular signaling and cellular receptors