MOLECULAR RADIOBIOLOGY

Question 1

It is a graphical relationship between various radiation dose levels and the magnitude of the observed response

Answer 1

Radiation Dose-Response Relationship

Question 2

2 importances of RDR

Answer 2

1. used to design therapeutic treatment routines for patients w/ cancer
2. radiobiologic studies have been designed to yield info on the effects of low-dose irradiation

Question 3

these usually follow high-dose exposure & an early response radiation-induced skin burns represent a deterministic response

Answer 3

Deterministic Radiation Responses

Question 4

Such responses usually follow low radiation exposure and appear as a late radiation response

Answer 4

stochastic responses

Question 5

The response is directly proportionate to the radiation dose

Answer 5

Linear Dose Relationships

Question 6

It intersects the dose axis at zero

Answer 6

Linear Non-threshold

Question 7

What are the examples of the linear non-threshold?

Answer 7

radiation-induced cancer, leukemia, genetic effects

Question 8

true or false? In linear non-threshold, any dose, regardless of size, is not expected to produce a response

Answer 8

False. Any dose, regardless of size, is expected to produce a response

Question 9

This indicates that even w/o radiation exposure, that type of response, such as cancer, occurs

Answer 9

Natural Response

Question 10

It intercepts the dose axis at some value greater than 0

Answer 10

Linear Threshold

Question 11

This relationship shows that at high dose levels, radiation is not so efficient because an incremental dose at high levels results in less relative damage than the same incremental dose at low levels

Answer 11

Non-linear Dose Relationships

Question 12

What are the classifications of irradiation of macromolecules?

Answer 12

Main Chain Scission
Cross-linking
Point Lesions

Question 13

this is the breakage of the thread/backbone of the long-chain macromolecule; a long single molecule is reduced into smaller molecules

Answer 13

Main Chain Scission

Question 14

What is the result of Main chain scission?

Answer 14

1. reduces the size of macromolecules

2. reduces the viscosity of the solution

Question 15

Some macromolecules have small spur-like molecules extending of the main chain

Answer 15

Cross-linking

Question 16

Cross-linking does what?

Answer 16

Increases the viscosity of the macromolecular solution

Question 17

What are Point Lesions?

Answer 17

• Disruption of single bond chemicals that result in P.L

- Can cause the modification of the molecule w/c can cause it to malfunction of the cells

Question 18

What are the results of Point lesions?

Answer 18

Results in late radiation effects at the body

Question 19

What are the different macromolecular syntheses?

Answer 19

Catabolism
Anabolism
Protein Synthesis
DNA Synthesis

Question 20

Difference between catabolism and anabolism

Answer 20

CATABOLISM - macromolecules are broken down into smaller molecules w/ the release of energy

ANABOLISM - construction of macromolecules from smaller molecules

Question 21

These are manufactured by translation of the genetic code from tRNA

Answer 21

Proteins

Question 22

info carried by the mRNA is transcribed into the newly synthesized protein

Answer 22

Protein Synthesis

Question 23

How many phases does DNA synthesis have and what are they?

Answer 23

Interphase (G1)
Interphase (S)
Interphase (G2)

Question 24

What are the different types of radiation-damaged human chromosomes?

Answer 24

Terminal Deletion
Decentric formation
Ring formation

Question 25

What are the 3 principal observable effects that may result from irradiation?

Answer 25

cell death
malignant disease
genetic damage

Question 26

What are the different radiation responses of DNA?

Answer 26

Main-chain scission w/ only single-strand break
Main-chain scission w/ double-strand break
Main-chain scission & subsequent cross-linking
Rung Breakage
Base Damage