Unit 2 (Molecular & Cellular Biology)

**the interaction of radiation in cells is a probability function or a matter of:

the initial deposition of energy occurs very rapidly – within a period of:

is radiation interaction in a cell selective or nonselective?

as a generalization, visible changes in
the cell's tissues and organs resulting from ionizing radiation are not:

biologic changes resulting from radiation occur only after a period of time known as a ___________ which depends on ___________ and varies from _____________________.

results of ionizing radiation interacting directly with macromolecules (DNA, RNA, proteins, etc.):

**absorption of ionizing radiation by the medium in which organelles are suspended, primarily water:

label A and B:

**—atom or atom group carrying an unpaired electron and no charge:

**a free radical is highly reactive because the unpaired electron will pair up with another electron even if it has to:

**explain what is happening in the diagram:

**after radiolysis of water explain what can occur:

**after radiolysis, give a common reaction at this stage and explain it:

**after radiolysis, give a common reaction at this stage and explain it:

**describe what can occur with the following ion pair H+ and OH-

**an example of an action of free radicals includes that they could come together. show what this would create with the free radicals H* and OH*

**an example of an action of free radicals includes that they could join with other free radicals, possibly forming a new molecule. show what this combination results in:

list three common actions of free radicals:

**A free radical can combine with oxygen and form a:
(give an example)

**show a chemical reaction we discussed that is an example of when a free radical may react with a biologic molecule:

—an indirect interaction usually produces __________ due to the presence of _________.

**—if oxygen is present, R* and H* may react with oxygen to form:

list the steps of the process of an indirect effect leading to biologic effects:

the rate at which ionizing radiation deposits energy as it travels through matter:

**what is LET measured in?

**which has more LET, gamma or alpha and beta?

produce ionizations that are distant from each other:

produce many ionizations in a short distance:

LET of x-ray, photoelectrons, and compton electrons:

**—dose from 250 kVp x-ray divided by the dose from another radiation source to produce the same biologic response:

if the LET increases, what happens to the RBE?

—a point mutation that commonly occurs with low-let radiations (high energy ionizing radiations):

creates a frame shift mutation that can make a change in DNA:

with what type of radiation is a double-strand break more common?

if a double-strand break is further exposed to radiation, what can result?

what can occur if a double-strand break occurs in the same rung of DNA?

**usually the interaction of high energy/low LET with DNA causes a loss or change in nitrogenous base on the DNA called a:

the chemical unions created between atoms by the single sharing of one or more pairs of electrons:

radiation induced chromosomal breaks manifest during which phase(s) of cell division?

what types of cells are subject to chromosome breakage?

chromosomal _____________ are when two or more segments appear.

what are some occurrences that can happen when chromosomal fragments appear?

what are the two types of chromosome anomalies?

when do chromosome aberrations take place?

when do chromatid aberrations take place?

label the types of damage that can occur in DNA:

after a low radiation dose, most cellular radiation damage that results in late somatic effects occurs because of:

areas on DNA molecules caused by the breaking of a single chemical bond:

**experimental data strongly supports that _____ is the irreplaceable master, or key, molecule that serves as the vital target.

**KNOW the 7 key cellular effects of irradiation:

what exposure amount can cause cell death?

in cell death, if enough cells of the same kind are killed, what can happen?

what exposure amount can cause reproductive death?

what is a positive aspect of reproductive death?

—**when a cell dies without attempting division during the interphase portion:

occurs when a cell dies after one or more divisions:

does mitotic death or apoptosis usually require more radiation dose to occur?

failure of the cell to start dividing:

what exposure amount can cause mitotic delay?

reasons for mitotic delay:

what occurs with the interference of function as an effect of irradiation?

the potential result when ionizing radiation interacts with  a DNA macromolecule:

**when broken ends of the chromosome rejoin with no visible damage:

denoting a chromosome fragment without a centromere:

chromosome having two centromeres:

transportation of two segments of nonhomologous chromosomes:

nonhomologous means:

when a broken chromosome segment is turned upside down:

when the broken fragments relocate to opposite arms of the chromosome:

what is happening on the chromosomal level for this to occur?

what is happening on the chromosomal level for this to occur?

how does downs syndrome occur?

a condition classified by a flattened nose and face, upward slanting eyes, single palmar crease, short fifth finger that curves inward, widely separated first and second toes and increased skin creases:

**a chromosome map produced when enlarged photographs of a cell’s chromosomes are cut out and each is paired with its sister chromosome:

karyotypes of human somatic cells show:

**records the relationship between an irradiated cell and the absorbed dose to determine radiosensitivity and is constructed from data obtained by a series of experiments:

**what type of LET curve offers a survival shoulder?

cell survival curve increases with:

list what these stand for:
LET
RBE
OER

if you have an increased RBE, what has happened to the LET? to the OER?

states that the radiosensitivity of cells is directly proportional to their reproductive activity and inversely  proportional to their differentiation:

who observed the effects of ionizing radiation on testicular germ cells in rabbits and when?

the higher the metabolic rate of the cell, the _______ the sensitivity to radiation.

hemopoetic cells are _____ sensitive to radiation than CNS cells.

cells respond differently to ionizing radiation depending on:

**describe how metabolic rate, maturity, and differentiation affect radiographic sensitivity:

**know sensitivity doses for the following:
hematologic depression
whole body dose
neutrophils
thrombocytes
CNS
spermatogonia
ova

undifferentiated (less specialized) and have rapid cell division:

differentiated (more specialized) and have slow cell division:

mature cells have ________ sensitivity than immature cells.

small cell lung spreads quickly and is _____________ as opposed to non-small cell.

**the only safe dose of radiation is: