Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Radiation Biology > Molecular and Cellular Radiation Biology - Week 3 > Flashcards

Molecular and Cellular Radiation Biology - Week 3 Flashcards

(70 cards)

Start Studying
1
Q

Radiation capable of removing an orbital electron from an atom
-can damage a system by ionizing(removing electrons) from the atoms comprising a molecular structure

A

Ionizing radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

T/F
Ionizing radiation can cause the atom to not bond properly in molecules and possibly affects the function of the atom

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

-mass
-energy
-charge
-velocity
-origin

A

Characteristics of ionizing radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What do the characteristics of ionizing radiation determine?

A

The extent of transfer energy to biological tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Large particle, travels a few inches

A

Alpha particle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Very small particle, travels a few feet

A

Beta particle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Alpha and beta particles

A

Particulate raditation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Small particle, travels a few feet

A

Neutron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

High energy, travels long distances

A

Gamma ray

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

High or low energy, travels long distances

A

Xray

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Neutron, gamma ray, xray

A

Electromagnetic radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the two main categories of ionizing radiation?

A

Natural/environmental radiation

Man made radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Cosmic, terrestrial, internal

A

Natural/environmental radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Xrays
Nuclear medicine isotopes

A

Man made radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Average energy deposited per unit length of track
**Determines the biological consequences of radiation exposure

A

Linear Energy Transfer (LET)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Expressed in units of keV/um (micron)

A

Linear energy transfer. LET

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the LET value of diagnostic X-rays

A

2-3 keV/um (micron)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Radiation includes particles that have substantial mass and charge, causing lots of ionization and interaction with tissues

A

High-LET
-alpha particles
-ions of heavy nuclei
-charged particles released from interactions between neutrons and atoms
-low energy neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Not as ionizing and randomly interacts with tissues keeping its energy and travelling further

A

Low-LET
-gamma rays
-X-rays

*small particle
*small mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

-Loses or deposits energy more rapidly
-energy is exhausted in a shorter length of track

A

High-LET
*doesn’t travel as far, but rapidly releases energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

T/F
High LET radiation can be very destructive to biological matter

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the relation between the level of LET and the chances of causing biological damage?

A

As LET increases, the chances of causing significant biological damage to radiosensitive DNA increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Causes damage primarily through an indirect action that involves the production of free radicals

A

Low-LET

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

-solidarity atoms that have unpaired valence electrons (open shell)
-very chemically reactive toward other substances (want to find an electron pair)

A

Free radicals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
T/F Low-LET radiation may directly induce single-strand breaks in DNA structure
True
26
T/F Because low-LET radiation generally causes sublethal damage to DNA, repair enzymes can usually reverse the cellular damage
True
27
-short wavelengths -high energy (will not interact in as much tissue) -travels further
Low-LET properties
28
-substantial mass and charge (alpha) -more likely to interact with biological tissue -lose energy rapidly -produce much more ionization per unit travelled (more damage) -do not penetrate as far
High-LET properties
29
T/F The LET of an alpha particle is 1000x the LET of an electron
True
30
What happens each time a particle interacts with DNA?
Loses energy and slows down
31
Does an electron interact more or less than an alpha particle?
Less and travels further
32
-Quantitatively describes the relative effect of LET -measures the biological effectiveness of radiation that have different LETs
Relative Biological Effectiveness (RBE)
33
What is the SI unit of absorbed dose?
Gy
34
What is the relation between LET and RBE?
As LET increases, RBE also increases
35
What RBE are diagnostic X-rays considered to have?
RBE of 1
36
Considered the type of ionizing radiation that was absorbed *used for protection purposes
Equivalent Dose (EqD)
37
(WR)
Weighting factor
38
The product of the average absorbed dose in a tissue and the radiation weighting factor (WR)
Equivalent Dose (EqD)
39
What is the radiation weighting factor (WR) for xray and gamma ray photons and electrons?
1
40
When irradiated in an oxygenated, or aerobic, state, biological tissue is more sensitive to radiation than when exposed to radiation under anoxic (without oxygen) or hypoxic (low oxygen) conditions
Oxygen effect Oxygen Enhancement Ratio (OER) quantifies the oxygen effect
41
Radiation produced biological effects from direct action (ionization) -the presence or absences of oxygen is of little or no consequence
High-LET (alpha)
42
Radiation produced biological effects from indirect action (formation of free radicals) -oxygen is needed for free radicals to form during ionization -without oxygen, no free radicals form and there is less cell damage
Low -LET
43
What is the OER of high-LET radiation?
Approx. 1
44
What is the OER of low-LET radiation?
Approx. 2-3
45
T/F If radiation damages germ cells, the damage may be passed on to future generations
True
46
T/F If enough somatic cells are affected by ionizing radiation, entire body processes may be disrupted
True
47
Biological damage occurs as a result of ionization of atoms on vital biological macromolecules which can cause these molecules to become inactive or functionally altered
Direct interactions
48
Refers to the effects produced by reactive free radicals that are created by the interaction of radiation with water molecules
Indirect interactions
49
Called a POINT LESION can result in a gene abnormality Commonly occur with low-LET radiation Repair enzymes are often capable of reversing this damage
Single strand break
50
-May be repaired, but not as easily as single strand breaks -If not repaired, further separation can occur in the DNA chains -Threatens the life of the cell -happens more commonly with high-LET radiation
Double strand break
51
When two interactions occur within the same rung of DNA, the result is a cleaved or broken chromosome with each CB new portion containing an unequal amount of genetic material
Double strand on the same rung of DNA
52
What happens if the damaged chromosome from double stranded break divides?
Each new daughter cell will receive an incorrect amount of genetic material Resulting in either death or impaired function of the new daughter cell
53
Occurs when a large number of cells are irradiated with a dose of 1000Gy in a short amount of time -causes DNA molecule to break up and cell proteins to coagulate
Instant death
54
Results from exposure of cells to doses in the range of 1-10Gy -the cell loses its ability to reproduce, preventing damage from being passed on
Reproductive death
55
Programmed cell death l, occurs when a cell dies without attempting division during the interphase portion of the cell life cycle
Apoptosis
56
How much radiation do radiosensitive cells require to induce apoptosis?
Less radiation (a few hundred cGy)
57
How much radiation do radioinsensitive cells require to induce apoptosis?
Require more (several thousand cGy)
58
Also called genetic death Occurs when a cell dies after one or more divisions
Mitotic death *dose required is very small
59
Can be caused by exposure as little as 0.01Gy just before division begins After the delay the cell may resume its normal function
Mitotic delay
60
Permanent or temporary interference with cellular function
Interference of function
61
Non specialized/undifferentiated Undergo rapid cell division
Immature cells
62
Specialized Highly differentiated Divide at a slower rate or do not divide
Mature cells
63
State that radio-sensitivity is: DIRECTLY PROPORTIONAL to their reproductive activity INVERSELY PROPORTIONAL to their degree of differentiation
Law of Bergonie & Tribondeau
64
What are some examples of radiosensitive cells?
-basal cells of skin -blood cells -intestinal crypt cells -reproductive cells
65
What are some examples of radioinsensitive cells?
-brain cells -muscle cells -nerve cells
66
T/F Blood count test for the purposes of dosimeter is not valid
True
67
Is epithelial tissue radiosensitive?
Highly
68
Permanent sterility
5-6Gy
69
Temporary sterility
2Gy
70
Can depress the male sperm population/suppress menstruation/cause genetic mutations in future generations
0.1Gy 100mSv

Radiation Biology (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions