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Unformatted text preview: e Hydrophilic head group: phosphate +
choline 1 fatty acid Absent from plants, bacteria Hydrophobic interactions phosphate glycerol sphingosine
fatty acid non-polar choline phosphate fatty acid choline polar fatty acid BIO 1140 – SLIDE 9 > The second experiment, this technique is commonly used to
asess how mobile a membrane consituant is. It is a technique
called FRAP ( Fluorescence Recovery After Photobleaching).
> So what happens is that u take a cell and u label membrane
components of intrest with the fluoresent marker. These could be
proteins or lipids. Than u direct a strong, highly focused laser at
part of the cell and u bleach the fluoresents. You over expose it to
light, so that it becomes bleached. Next u look to see how quickly
> If the component that u labeled is mobile, than it will quickly move
into the bleach area, and the fluresence will come back. If it is not
mobile, than that bleached spot will remaine. Fig. 7-11 Becker et al. 2009 Nonpolar
The lipid bilayer Gorter and Grendel, 1925 Key component of permeability
barrier Composition I if Mobile it will
mobile it will stay
low > What makes up the lipid bilayer? The back bone of the membrane is a lipid
bilayer. The membrane is made up of two layers of lipid. This lipid bilayer
becomes the structural basis of the membrane. There are Three types of lipids
that are found in it.
1) Phospholipids: The bluck of the membrane is made up of phospholipids.
And there are two main kinds of phospholipids. phosphoglycerides and
phosphoglycerides: This is the larger component. They are built on a glycerol
backbone, glycerol is a three carbon molecule, to two of those carbons are
attachd fatty acid chains. Fatty acids are hydrocabon chains, if every carbon is
filled up with the maximum # of hydrogens, they are called saturated, and u
have a series of singal bond. If in some cases u see double bonds, than it is
said to be unsaturated fatty acid. This is imporatnt in a membrane context b/c
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This note was uploaded on 02/19/2014 for the course BIO 1140 taught by Professor Fenwick during the Winter '07 term at University of Ottawa.
- Winter '07