Biological Membranes
[1] Number of Detergent Molecules per Micelle
Lehninger chapter 11, page 432, question 3
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See answer in Lehninger on page AS–11.
[2] Properties of Lipids and Lipid Bilayers
Lehninger chapter 11, page 432, question 4
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See answer in Lehninger on page AS–11.
[3] Length of a Fatty Acid Molecule
Lehninger chapter 11, page 432, question 5
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See answer in Lehninger on page AS–11.
[4] Membrane Self-sealing
Lehninger chapter 11, page 432, question 11
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See answer in Lehninger on page AS–12.
[5] Flip-Flop Diffusion
Lehninger chapter 11, page 432, question 13
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See answer in Lehninger on page AS–12.
[6] Membrane Permeability
Lehninger chapter 11, page 432, question 14
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See answer in Lehninger on page AS–12.
[7] Creating and Interpreting the Hydropathy Plot
Kyte and Doolittle (1982) developed the SOAP algorithm which is the standard method for finding membrane spanning regions in protein sequences. An implementation of SOAP is available in the
Hydropathy Plot Tool spreadsheet. Use this tool to generate hydropathy plots for the proteins
rhodopsin,
cytochrome b5 and
lysozyme. One of these proteins is a single-pass integral membrane protein, one is a multi-pass (7) integral membrane protein and one is a globular protein that does not exist in a membrane. Interpret the hydropathy plots to match topology with protein.
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The protein rhodopsin is a seven pass transmembrane protein. Cytochrome b5 is a single-pass transmembrane protein. Lysozyme is a globular protein. See hydropathy plots below where horizontal red bars approximate the membrane spanning sequences. Note that the abcissa is scaled according to protein length.
[8] Use of the Helical Wheel Diagram
Lehninger chapter 11, page 433, question 15
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See answer in Lehninger on page AS–12.
[9] The Fluid Mosiac Model of Biological Membrane Structure
Lehninger chapter 11, page 433, question 26
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See answer in Lehninger on page AS–12.
