16 Questions
What is the primary effect of ionizing radiation at the physical stage?
Transfer of kinetic energy to atoms or molecules
During which stage is the absorbed energy of ionizing radiation displaced into molecules and between them?
Physicochemical stage
What is the outcome of the reactions between free radicals and intact molecules at the chemical stage?
Formation of molecules with abnormal structure and function
At which stage does ionizing radiation lead to the development of processes of biological damage and reparative processes?
Biological stage
Which stage involves the formation of injures on all levels from cellular structures to organism and population?
Biological stage
What is the period over which the biological effects of ionizing radiation at the biological stage occur?
Seconds to years
What is the basic mechanism that triggers events causing radiation damage to living tissues?
Absorption of energy from IR produces damage to molecules by direct and indirect actions
What occurs if particles or photons transfer sufficient energy to remove 1 electron from the inner orbital shell to the outer orbital shell?
Excitation
What is the result of ionization of atoms on key molecules in a biological system?
Inactivation or functional alteration of the molecule
What does indirect action of radiation involve?
Transfer of energy to an atom with decay to free radical species
What is the effect of oxygen on free radical formation?
Oxygen can modify reactions by enabling the creation of other free radical species with greater stability and longer lifetimes
What does the absorption of energy from IR result in?
'Ionization or excitation'
'Ionizing radiation + RH' results in:
'R- + H+'
'Indirect action involves production of reactive free radicals damage to key molecule with biological effect' - This statement is true for:
'Radiolysis'
'Formation of molecules with abnormal structure and function' occurs in:
'Biological stage'
'Water molecule absorbs energy and disassociates into 2 radicals with unshared e’ in valance shell' - This process is known as:
'Radiolysis of H2O molecule'
Study Notes
Physical Stage of Ionizing Radiation
- The primary effect of ionizing radiation at the physical stage is the absorption of energy by molecules.
Chemical Stage of Ionizing Radiation
- During the chemical stage, the absorbed energy is displaced into molecules and between them, leading to the formation of free radicals.
- The reactions between free radicals and intact molecules result in the formation of molecules with abnormal structure and function.
Biological Stage of Ionizing Radiation
- Ionizing radiation leads to the development of processes of biological damage and reparative processes at the biological stage.
- This stage involves the formation of injuries on all levels from cellular structures to organism and population.
- The biological effects of ionizing radiation at the biological stage occur over a period of time.
Mechanism of Radiation Damage
- The basic mechanism that triggers events causing radiation damage to living tissues is the removal of one electron from the inner orbital shell to the outer orbital shell, resulting in ionization.
Ionization and Radiation Damage
- When particles or photons transfer sufficient energy to remove one electron from the inner orbital shell to the outer orbital shell, ionization occurs.
- Ionization of atoms on key molecules in a biological system results in radiation damage.
Indirect Action of Radiation
- Indirect action of radiation involves the production of reactive free radicals, leading to damage to key molecules with biological effects.
- The indirect action of radiation occurs in the presence of water molecules.
Effect of Oxygen on Free Radicals
- Oxygen enhances the formation of free radicals.
Absorption of Energy from IR
- The absorption of energy from IR results in the formation of reactive free radicals.
Water Molecule Disassociation
- When a water molecule absorbs energy, it disassociates into two radicals with unshared electrons in the valence shell, a process known as radiolysis.
Test your knowledge on the biological effects of ionizing radiation, covering stages such as physical, physicochemical, chemical, and biological. Explore the transfer of kinetic energy, formation of free radicals, and reactions involved in this process.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
