What proteins are marked?
Surprisingly many of the proteins created in
the cell are faulty from the start. They must be broken down and
rebuilt since they can damage the organism. But perhaps the most
important reason for a cell to get rid of a protein is that in
this way the cell can control a given chemical reaction. By quickly
destroying a protein that has a special function, the cell gets
the same result as when one turns off a switch. When the proteins
have been hacked to pieces, the cell can use their amino acids
to synthesize other proteins. When protein degradation does not
function correctly, we can become ill.