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24 Cards in this Set
- Front
- Back
- 3rd side (hint)
Lipids (types)
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Cholesterol
Spingolipids (2) Glyceryl Phospolipids(6) |
spingo- Sphingomyelin
gangliosides Glyceryl phospolipids: Phospatidylcholine(PC) ethanolamine(PE) glycerol(PG) serine(PS inositol(PI) cardiolipin(CL) |
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Amphipathic
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hydrophobic and hydrophilic
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Lipid Bilayers Form by
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self assembly and it is
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inherent and rapid and spontaneous
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Lipid bilayers are
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cooperative structures which makes them
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extensive close compartmentalizing and self-sealing
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Forces that stabilize lipid bilayers
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Hydrophobic is primary
Van der Waals betwen tails Electrostatic between polar heads and water |
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Liposomes form by?
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Create a vehicle out of small membrane.
Sonicated phospholipids around 50 nm allows water soluble drugs to get into aqueous compartments drugs or dna therapy |
in the future targeting signals can be added for better targeting
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Proteins in bilayer
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1Integral
2-Peripheral |
1need detergent or organic solvent to get them out
2 loosely associated only need mild conditions |
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protein arrangement
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span membrane with alpha helices
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composed of hydrophobic amino acids, cytoplasmic will be hydrophilic
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protein arrangement channels
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beta pleated sheets
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hydrophobic AA are on outside of pore, while hydrophilic ones line the channel
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Prostaglandin H2 synthase-1
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substrate arachidonic acid does not have to leave hydrophobic environement to reach active site of membrane
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Aspirin inhibits prostaglandin synthesis by transferring acetyl group to ser530 of channel, which blocks access
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Peripheral membrane proteins can associate with membrane by
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hydrophobic groups!
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Protein and Lipid Mobility
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Lateral diffusion is fast
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trasverse (flip flop) is slow
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Hybridoma
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mixing of cell membranes when two cells get heated and undergo lateral diffusion
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membrane fluidity
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controlled by fatty acid composition and cholesterol content
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double bonds lower melting point (unsaturated fat)
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Diffusion Across Membrane
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Hydrophilic slow
hydrophobic fast diffusion high to low rate of diffusion is diffusion constant times Concentration on side 1 over side 2 |
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Lipophilic molecules
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Simple diffusion
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shed water shell
moves into fatty core diffuses out by con. gradient resolvated |
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Channel details
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passive transport
around 100000 ions a second examples |
voltage gated Na channel
ligand gated AchR cAMP reg Cl- channel other pressure sensitive |
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Transporter details
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around 100-1000 per second
active/ passive |
passive glucose
active 1- ATPase- Na/K pump 2- redox coupled-- respiratory chain 3 atp binding cassette multidrug resistance protein transport 4- 2 na dep glucose transporter |
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Energetics
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uncharged particles rate depends on concentration
charged particle depends on membrane potential |
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Examples of Channels
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Sarcoplasmic reticulum Ca++ ATPase
Na-Glu symporter K+ channel |
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SarcoER Ca++ ATPase
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uniporter
primary active transporter steps(6) |
1binding
2phos 3eversion 4release 5hydrolysis 6eversion |
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Na Glu symport
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secondary active transport
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K channel
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uniport
passive transport voltage gated selectivity determined by amino acids lining the pore |
cone shaped
TVGYG pore ball and chain occlusion |
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Ionophores
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compounds that collapse ionic gradients
small molecules that surround ions and shuttle them valinomycin cyclic peptide that binds K+ monensin- Na gradients |
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