Question

Organic Chemistry II: Please read the whole question and then answer with details and clear typing. NO HAND-WRITYNG PLEASE.

Not too long ago "free radicals" and quenching those "free radicals" was a big marketing push. We were told we needed to consume or apply antioxidants (in the marketed mixture of the day) in order to reverse or prevent free radical damage.

Please post a short description of an example of where some free radicals might originate and a potential antioxidant quench to eliminate them. Don't forget to discuss HOW the antioxidant would quench those radicals.

Your answer should be 150 words.

THE ANSWER MUST BE TYPED SO I CAN READ IT. PLEASE NO HAND-WRITING.

Answer 1

An antioxidant is a substance that at low concentrations delays or prevents oxidation of a substrate. Antioxidant compounds act through several chemical mechanisms: hydrogen atom transfer (HAT), single electron transfer (SET), and the ability to chelate transition metals. Here with radicals it'll go with SET mechanism. The main characteristic of a antioxidant system is the prevention or detection of a chain of oxidative propagation, by stabilizing the generated radical. That is actually the quenching a spontaneous radical reaction.

Here hydroxyl radical(antioxidant) reacts with guanine i.e the base pair of DNA. Which actually quenching other reactions with guanine. As we can see here hydroxyl is taking part in reaction with radical, generated in guanine and in each step it gonna suppress the potential of that guanine radical to react further to polymerization or some other radical reactions. This is the role of antioxidant.