If a macromolecule has (a) ______, it will break down into smaller molecules.
main-chain scission
In vitro radiation of macromolecules causes ______damage to macromolecules.
repairable and reversible
The most radiosensitive macromolecule is:
DNA
DNA is contained in the _______ of the cell nucleus.
chromosomes
A type of DNA damage that may not be reversible is a _______.
Base change or loss
Radiation damage to DNA can result in ____.
Cell death, malignant disease, or genetic changes.
Molecular lesions of DNA are called:
Point Mutations
The principal radiation interaction within the human body is with _____.
water
The disassociation of water molecules following irradiation is termed:
Radiolysis
When an atom of water is irradiated, it first dissociates into what?
an ion pair
Two OH* free radicals can join to form _____molecules.
hydrogen peroxide
Free radicals can be damaging because they are ___.
unstable and highly reactive
An indirect effect from ionizing radiation occurs on a ____ molecule.
water
Ionizing events from irradiation are considered to be direct effects if they occur with _______ molecules.
DNA
The principal radiation interactions within the human body are assumed to be ____.
indirect effects
(Ionizing event) H2O + Radiation --->
HOH+ + e-
(Additional Ionization) H2O + e- --->
HOH-
(Reactive By-Products) HOH+ dissociation --->
H+ + HO*
(Reactive By-Products) HOH- dissociation --->
OH- + H*