Free Radicals

[Alkatran]

I was talking with my girlfriend and "Free Radicals" came up. I told her I didn't know what they were and she said "ummm... I think they were... oxygen missing an atom..." Anyways she was saying they caused cancer and that fatty foods caused them, so you should eat green stuff...


Anyways I looked it up and I want some confirmation on what I found out.

-Free radicals are substances which are missing a valence electron and are therefore highly reactive. This allows them to break the carbon-carbon double bond in some molecules
-Free radicals are 'nullified' by anti-oxydants, which bond with them
-The body produces free radicals all the time (due to cellular respiration?), more so when exercising
-The body has an anti-oxydant system which can take care of most free radicals
-Green vegetables etc contain anti-oxydants (so they reduce free radicals, and meat just doesnt reduce them as opposed to causing them)
-The immune system uses free radicals to mark foreign substances

So: free radicals are bad, unless you don't have enough. Exercise is giving us all cancer, and green vegetables harm the immune system. :D

[Bronze Dog]

Originally posted by Alkatran
So: free radicals are bad, unless you don't have enough. Exercise is giving us all cancer, and green vegetables harm the immune system. :D

Funny. :)

Suspect that you may have a few things to post in the "Experiences of dating/being married to a woo" topic if you haven't already. (Recently bumped in General Skepticism and Paranormal.)

[geni]

Originally posted by Alkatran
-Free radicals are substances which are missing a valence electron and are therefore highly reactive. This allows them to break the carbon-carbon double bond in some molecules


Some free radicals can do that. Pretty much true though.

[pgwenthold]

Originally posted by Alkatran
-Free radicals are substances which are missing a valence electron and are therefore highly reactive. This allows them to break the carbon-carbon double bond in some molecules


Among other things. Radicals will add to double bonds, creating another free radical that can propagate. Another common process is hydrogen atom abstraction. Hydroxyl radicals and superoxide ions can abstract hydrogen from organic molecules, such as proteins or DNA, thereby messing up their function.

In fact, there is a class of drugs based on the idea that free radicals can pluck hydrogen atoms out of the DNA backbone, causing the DNA to fragment and not proliferate. In the early nineties, there was a lot of work in trying to turn this into a cancer treatment, to target fast growing cells. However, the process is so efficient that, as they say, "the rat died before the cancer cells did." IOW, the drugs wiped out everything.




-Free radicals are 'nullified' by anti-oxydants, which bond with them


In a lot of cases. In other cases, the anti-oxidant is just something that is more readily reduced than the biomolecules. That's the way I usually view them.


-The body produces free radicals all the time (due to cellular respiration?), more so when exercising
-The body has an anti-oxydant system which can take care of most free radicals
-Green vegetables etc contain anti-oxydants (so they reduce free radicals, and meat just doesnt reduce them as opposed to causing them)
-The immune system uses free radicals to mark foreign substances

So: free radicals are bad, unless you don't have enough. Exercise is giving us all cancer, and green vegetables harm the immune system. :D

Free radicals around in too much quantity (and that doesn't need to be much) can certainly cause problems (consider, for example, that sunburn is technically a radical process). OTOH, the body itself is going to have a really hard time generating so many free radicals to kill itself, because as they get higher in concentration, the processes that cause them stop working.

The other thing to note is, like sunburn, damage caused by free radical chemistry is fixable. Some cells die earlier than they should, but the body has repair mechanisms for such things.

Note the aforementioned dead rats resulted from deliberate addition of a lot of free radicals specifically generated in the correct place (intercalated into the minor grove of DNA) to do as much damage as possible.