molecular radbiology chapter 34 Flashcards
The principal radiation interaction in the
body
Radiation Interaction With Water
Irradiation outside of the cell or body
In Vitro
Irradiation with the cell or body
in Vivo
A liquid that contains dissolved substances
Solution
The breakage of the backbone of the ling chain macromolecules
Main-Chain Scission
Process of side spurs created by irradiation
& attached to a neighboring macromolecules
or to another segment of the same molecule
Effect: increases the viscosity of the
macromolecular solution
Cross-Linking
Any change that results in the impairment or
loss of function at the point of a single
chemical bond
Not detectable
Point Lesion
The reduction of nutrient molecules for
energy
Catabolism
The production of large molecules for form
and function
Anabolism
consists of catabolism and
anabolism!
Metabolism
Process of forming a protein molecule from
messenger RNA
Translation
Process of constructing mRNA
Transcription
More abundant than nucleic acids
Less radiosensitive than nucleic acids
Proteins
The most important molecule in the body
Not abundant in the cell
DNA
most radiosensitive molecule
DNA
Deoxyribose, phosphate & base molecules
accumulate in the nucleus
DNA is in familiar double-helix form
G1 Portion of Interphase
The DNA separates like a zipper
Two daughter DNA molecules are formed
S Portion of Interphase
Control the growth & development of the
cell
Chromosomes
It represents the principal radiation
interaction in the body
Irradiation of Water
An uncharged molecule that contains a
single unpaired electron in the other shell
Lifetime: < 1 ms
Free Radical
Poisonous to the cell & therefore acts as a
toxic agent
Hydrogen Peroxide
The principal damaging product after
radiolysis of water along with Hydrogen
peroxide
Hydroperoxyl Radica
If the initial ionizing event occurs on the
target molecule
Direct Effect
If the initial ionizing event occurs on a
distant, noncritical molecule
The energy is transferred to the target
molecule
Indirect Effect