Presentation Transcript
Target Theory :Target Theory Presented by:
Joshua Nicolaas
Objectives :Objectives Define target theory
Explain target
Inform of different ways of LET
Explain irradiation
Types of hit
Target Theory :Target Theory Definition of target theory
DNA
Target
LET :LET Linear Energy Transfer
3 different ways of LET:
Low LET with anoxic
Low LET with aerobic
High LET
High vs. Low LET :High vs. Low LET
Target Irradiation :Target Irradiation Irradiation (hits)- the process by which an item is exposed to radiation
2 types:
Direct effect
Indirect effect
Summary :Summary Target theory says that there are sensitive critical molecules, that are important for cell survival and that radiation of these cells can cause cell death.
Target is the area of the cell that contains the target molecule.
Different ways of LET are; Low LET anoxic, Low LET aerobic, and High LET.
Irradiation is the process by which an item is exposed to radiation.
2 types of hit: direct and indirect effects.
Questions :Questions (T/F) High LET ionization are so close together that the chance for a indirect hit higher.
False
(T/F) Direct and indirect effect can’t be distinguish for each other.
True
Give an example of a high and a low LET
High= alpha particle, low = gamma ray
What is a target?
the area of the cell that contains the target molecule.
Questions :Questions (T/F) Adding oxygen to high LET radiation has no effect on the cell
True
What are the four things that can happen after mutation?
Death, teratogenic, somatic, genetic
What is more dangerous for the cell direct effect or indirect effect?
Direct effect
The process by which an item is exposed to radiation.
A) mutation C) ionization
B) irradiation D) non of the above
Questions :Questions Which has a better chance for hitting the target? Low LET in anoxic state or Low LET in aerobic state
Low LET in aerobic state
Target theory says that there are sensitive critical _______, that are important for cell survival.
Molecule
References :References Essentials of Radiation Biology and Protection, Steve Forshier
Biophysical journal, http://www.biophysj.org/cgi/content/full/78/4/1698
Britannica, http://www.britannica.com/EBchecked/topic/583497/target-theory#tab=active~checked%2Citems~checked&title=target%20theory%20--%20Britannica%20Online%20Encyclopedia