Lipids are a major component of cells. Lipids can be separated from
rather easily, because lipid does not dissolve well in water. Lipid removal is desired before protein
purification processing, because lipids would interfere with the separation
of the different kinds of proteins.
Separation of the lipid from the protein can be done by first gently
mashing the cells to make their lipids and proteins.
Then, the cellular debris
is stirred into a mixture of two different
that do not dissolve in each other. The mashing does not break the
basic atomic bonding in lipids and proteins, so proteins can be recovered
intact from the solvent that contains the protein. The solvent with
the lipid fraction can be thrown away.
This would be a good time to
perform activity #1, if it
fits with the class schedule.
Fats tend to self
organize like this in water, rather than dissolving.
But they do dissolve in organic solvents, whereas proteins
U.S. Department of Agriculture
scientist extracting cellular components