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>Having read Richard Vann's article on O2 exposure management in
>Aquacorps I think I understand that if O2 enters the respiratory chain
>prematurely molecules such as superoxide anion and hydrogen peroxide
>can form, if the O2 is at excess pressure these can overwhelm the
>ndeactivating superoxide dismutase and catalase. This is part of the O2
>problem.

>Now . . . .here it comes, are superoxide anions and hydrogen peroxide
>what we know as free radicals? and if they are can this effect be
>countered partially .by the intake of quantities of anti-oxidants as
>are found at drug stores? or is this all hokum?

Hydrogen Perioxide is definitely NOT a free radical.  A free radical
is typically seen as an atom or molecule that has a valence shell with
one unpaired binding electon.  This makes these molecules VERY
reactive.  

A simple example of a free radical occurs when we had light to
chemicals such as Boron (Br2).  When Br2 splits, it does so via a
heterolytic cleavage and leaves each Boron atom with 7 electrons in
its valence shell.  

I have not had the pleasure of reading Vann's article (where can it be
found, please?), and as such I do not know the chemical makeup of a
"superoxide anion" so I cannot determine if it is a free radical,
however, I will note that molecules that breat up homolytically
typically form ions.  Their valence shells are filled and for the most
part they NOT free radicals (however, there are free radicals that
have charges).

Hope everyone had a happy new year :^)

-Carl-

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