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Unformatted text preview: aturated fatty acids are nice stright linear fatty acids as shown in this example
here. Unsaturated fatty acids have a kink/bend every where they have a double
bond, this becomes important in membrane properties. So these are
hydrocarbon chains extending down one way to the third carbon of the glycerol
backbone, is linked through a phosphate group a polar head group called the (rgroup), b/c there are four main polar head groups which are: Choline,
ethanolamine, insitol and serine. The example here has choline as the rgroup, therefore this phosphoglyceride is called phosphoatidylcholine, b/c of the
presence of the phosphate and these polar head groups, the head end of the
molecule is polar and hydrophilic (water loving). The hydrocarbon chain of
the fatty acids are non-polar and are hydrophobic (water fearing). This
molecule has an hydrophobic and hydrophilic end, and this makes it an
amphipathic molecule. in phosphoglyceride u see typically 16-18 carbons in
the fatty acid chains and one fatty acid chain will be saturated and the other will
be unsaturated. > Sphingolipids: They are built on a sphingosine backbone.
Sphingosine has a long hydrocarbon chain as part of the molecule itself.
Sphingolipids have only one fatty acid attached to them. The
sphingosine backbone provides the other hydrocarbon chain. So
structurally they are very similar to phosphoglycerides, but there is only
one fatty acid chain. A particular important sphingolipid is
sphingomyaline. In sphingomyaline the head group is phosphate and
> when u dump these amphipathic molecules into water the
hydrocarbon chains tend to cluster together b/c of hydrophobic
intercations trying to get away from water. They tend to be on the
interior with the hydrophobic head groups facing towards the water. It is
b/c of this that u get a lipid bilayer. 2) Glycolipids: Are very similar in structure to phospholipids, the
main difference is that instead of a phosphate and r-group, they
have sugars. They can have single sugar units or strings...
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- Winter '07