How do we protect
ourselves against us?
Well, fortunately, if free
radicals don't encounter something,
they do spontaneously decay.
So those the
electron gets paired
and it will no longer be a free
radical and quite so reactive.
We have a number of enzymes,
superoxide dismutase (SODs)
that will turn superoxide free
radical with a couple protons
in the hydrogen
peroxide and oxygen
and we can further breakdown that
hydrogen peroxide in just a second.
So we have ways to degrade it.
And we have high levels
of these enzymes,
where we expect high levels of
free radicals to be generated.
We have circulating and then in
A glutathione peroxidase system,
and glutathione is a tripeptide.
It's gamma-glutamyl cysteine glycine,
which has a free self hydro-group,
when it encounters oxygen free
radicals that scavenges it
and by making a disulfide bond and
then the glutathione peroxidase
turns that disulfide
back into the native glutathione
and we're good to go.
So we have another mechanism
and this is a normal tripeptide
and a normal enzyme that exists
exclusively to clear free radicals.
Catalases, I mentioned we have a
way to get rid of hydrogen peroxide,
and we could break that
down into water and oxygen.
So we have multiple
by which we can protect
ourselves against free radicals.
And we've also talked already about free
radical scavengers such as Vitamin E.
And it turns out that there
are other proteins that
we have circulating such a
ceruloplasmin and others,
whose job it is to wander
around, find a free radical,
scavenge it and inactivate it.
let's talk about
And this is also an important mechanism
by which we can get biochemical injury.