Question

Discuss the mechanisms of DNA damage induced by sparsely (low LET) ionizing radiation (e.g., x-rays and -rays) via indirect damage by OH radicals.

Answer 1

DNA damage is the change of the basis striueture of DNA_, such as I break in a strand of DNA or may be a base is missing from the backbone of DNA. The majority of DNA damage caused by gladiation is due to chemical reaetion with water in celli LOH radicals are produced as the byproduct of Fenton's reaction of H202 and Fezt, most reactive and able to damage DNA These radicals react with DNA bare by adding to the double bonese Labstracting HL atoms from methyl groups and attacked the nearby sugar residiel. OH radical induces an imidazole ring opening in adenine and quanine to form fragmented purine. L Not only attacking the DNA base these radical can also break the DNA in single strands. 2300 single stand breaks pereell per Lhown in mammalian cell. The orcidation of Lipids by the radicals, generates aldehyde produets which can react with Ladenine quanine and eyto sine and form mutagerie Ladduets CDNA segment bound to cancer causing chemical).