Finals Material Flashcards
What do carbohydrate do
Provide energy and structure
What are the component of proteins and its function
They’re made up of amino acids and is made of primary, secondary, tertiary and quaternary structures
They provide structure and function
DNA and RNA is made up of _______ and they contain _______ that tells cells how to divide and operate
Made up of NUCLEOTIDES
Contain GENETIC INFO
DNA is ______ strand while RNA is ______ strand
DNA is double strand
RNA is single strand
Lipids provide ____ and _________
Provide energy and cell membrane
What is the function of ribosomes
Protein synthesis
What is the function of the lysosomes
Contains enzymes capable of destroying the cell
What is the function of the Golgi
Concentration and segregation of products for secretion
When the cell divides (mitosis), it forms _______
Chromosomes
DNA doubles during which cell phase
DNA Doubles in S-Phase
Put the interphase phase in the correct order
G0
G1
S
G2
What are the phases in mitosis
(PMAT)
Prophase
Metaphase
Anaphase
Telophase
Organelles replicate in which phase
G2
Cells cease division in which phase
G1
The _______ phase transition is the most radiosensitive
G2/M transition
What happen in G0 phase
This phase is postulated for cells that usually do not divide but are capable of being recruited into the cell cycle and division if needed
In metaphase the chromatids are ______
Metaphase, the chromatid are aligned on the equatorial plate in the center
In prophase, the chromatids are ______
Filamentous and visible
Just looks like a very stringy blob
During anaphase, the chromatids ________
They pull and migrate to opposite poles of the cells
During telophase, the chromatids ______
Are separated and has 2 separate membrane
DNA replicate during ________
Interphase
The acute effects of radiation are due to a reduction of _____ cells
Parenchyma cells
Dq is …..
The capability of the cell to repair it self
Apoptosis is a characteristic of _______
Interphase death
The interaction of an incident photon and a tightly bound inner shell electron which ejects an electron only to have the shell filled by an outer shell electron or an electron outside an atom is know as _______
The photoelectric process (or characteristic radiation)
Theoretically, the portion of the cell that is the target of radiation is the _______
The nucleus because it contains the DNA
During this phase of mitosis, chromatin becomes filamentous and visible
Prophase
The lease common DNA lesion resulting from Low LET radiation damage is ______
Double strand break
The law of Tribondeau and Bergonie states that:
Actively dividing cells are radiosensitive
Undifferentiated cells are radiosensitive
Cells with long mitotic (long diving) future are radiosensitive
The rungs of the ladderlike DNA molecule which connect the 2 sides of the double helix are composed of
Nitrogenous bases
Mitotic delay and mitotic overshoot are characteristic of ____
Division delay
What are the 3 fates for cells after irradiation
Division delay
Interphase death
Reproductive failure
What damage needs to occur at the level of DNA for chromosomal damage to occur
Double strand break
Direct damage causes _____ break which will result in more permanent DNA damage
Double strand break
What are the ways DNA can be damage
SBS
Dsb
Interstrand cross link
Dimmer formation
T/f
SBS causes cellular death
False.
Dsb causes cellular death
What the main the of DNA damage (strand break) we like to see in terms of therapeutic radiation
Double strand break
A __________ is the visible state of genetic material during a phase of the division of the cell (METAPHASE)
Chromosome
The sticky ends of the chromosome is repaired by ______.
Repair proteins
What are the 3lethal chromosomal aberrations
Dicentric
Bridge
Ring/ loop formation
If there’s 2 chromosome and there’s 1 dsb on each, what can that result in
A lethal dicentric and an acentric
OR
2 NON-lethal translocation
What are the 3 fates/ processes of irradiated cell
Division delay
Interphase death
Reproductive failure
During division delay, cells are delayed from ________
Entering mitosis
Since division delay is dose dependent, how can you over come division delay
Can overcome division delay by increasing the dose
Interphase death is also known as ….
Non-mitotic death
What happens in interphase death
Cell death occur before entering into mitosis and is characterised by apoptosis
T/f
Reproductive failure is an immediate death
False
Reproductive failure is NOT immediate cell death because due to its inability to repeatedly undergo division, eventually, the daughter cells will have inadequate info and will undergo cell death
What is Dq
It is the quasi threshold aka the shoulder
It indicates the cells ability to repair damage
Dq is dependent on…
Type of radiation (direct or indirect), cell type and the condition of the cell
The larger the shoulder, the larger the Dq, so ______(more/less) radiation is required to obtain equivalent amount of cell death
The more radiation is required
(X-rays have larger a shoulder than alpha particles. So you need a lot of X-rays to cause cell death whereas alpha particles have NO shoulder so cell death is inevitable)
What is D0…
It is 1/slope
It’s the dose required to reduce the fraction of cells surviving to 37 percent.
What is D10…. And how do you calculate it
The dose required to reduce cell survival to 10 percent
D10 = (2.3)(D0)
What are the 2 distinct terms for DNA damage
SLD and PLD
SLD can be ______ and is measure by ______
Can be repaired and is measure by the Dq (ability to repair damage)
PLD are potentially lethal damage and can be repaired, especially under sub-optimal growth conditions. What are some suboptimal conditions
Hypoxia
Inadequate nutrients
The sub-optimal conditions will cause cells to _____
STOP cycling. So with the cease in cycling, the are given time to repairs these lethal damages
How is plating efficiency calculated
(Number of cells plated) x (percent of them that grew)
Densely ionizing worlds through ________ action/damage
DIRECT
Sparsely ionizing works through _______ action/damage
INDIRECT
Radiosensitizer and radio protectors only work for _______
Sparsely ionizing
Radiosensitizer added to sparsely will make the survival curve move to the ______
Left
Rdaioprotector added to sparsely will make the survival curve move to the ______
Right
As D0 decreases, cells become more _____
Sensitive
As D0 increase, cells become more ______
Resistant
What is the impact of apoptosis on the cell survival curve
When apoptosis is ocurring, the cells are more sensitive and curve much steeper, much deeper thus D0 decreases and more sensitive to radiation.
The 4 R’s is based on ______
Fractionation
What are the 4 R’s
Repair (deals with normal tissues)
Redistribution
Reoxygenation
Regrowth
*deals with the cancer tumor
Fractionation allows for repair of ______
Sub lethal damage
You never give a single dose in radiation therapy. You fraction because fractionation, you repeat the shoulder. This allows for ________ to repair
Normal tissue to repair
**rememeber, tumors don’t repair damage as well as normal tissue because they have lost repair proteins
High LET will kill both _____ tissues and _______tissues due to the direct DNA damage
High LET kill both normal tissue and Tumor tissue
Higher dose are required when we fractionate because each time we fractionate, we repeat ____
Dq (the shoulder, the cell ability to repair damage)
Fractionated doses increase _____
RBE (Relatively Biological Effectiveness)
What’s the principle of redistribution of radiobiology
Principle of cells moving into different phases of cell cycle between fractions. G2M are most sensitive. If you gave all the radiation at once (single fraction) you kill all G2M leaving G1 and S to regrow. By fractionating, the G1 and S cells will eventually recycle and move into G2 again.
notes
In X-rays and therapeutic, we work with photons and electrons that work through indirect action and indirect is greatly dependent on free radicals. With out free radicals, therefore without oxyge, we dismish the amount of dsb DNA
True
What is the concept of reoxygenation in radiobiology
Idea is to max amount of oxygen in order to max radiation effectiveness. O2 makes cells more sensitive to radiation. Fractionation kills oxygenated tumor cells and allow the hypoxia cells to get some air.
**remember: neutrons and alphas make no difference if o2 is present or not.
Oxygen enhancement ratio (OER) max is _____
3
OER decreases as LET ______ (so alphas and neutrons have a small OER)
Increases
Which of the 4 R’s is the negative side of fractionation.
Regrowth.
In between fractions, tumors can regrow. Tumors get angry as you give radiation so as you go through radiation, the tumor adapts and grow faster. This is very common in H+N tumors (aka accelerated regrowth)
What is the distance of O2 diffusion at the arterial end of capillary
70 micro
RBE measure ________
Radiation quality
Every radiation type is compared to a _____kV xray
250 kV xray
*dose at 250 kV of xray test to get same effect
max RBE is ____
10
RBE increases as LET ______ up to max of 100 keV/uM
Increases
Acute and late “effects” refers to when the damage _____
Manifest itself
Acute and late “responding” tissues refers to when the damage _____
Have occurred
Acute effects is caused by depletion of ______ cells and can be ______
Parenchyma cells and can be reversed
Late/chronic effects is caused by depletion of _________ cells and is _______
Stromal cells and is irreversible
List acute effects
Inflammation
Edema
Hemorrhage
Denudation
List chronic effects
Fibrosis Atrophy Ulceration Stenosis Obstruction
Early responding tissues appear soon after injury and consist of ________________
VIM and DIM cells (rapidly diving)
So skin, bone marrow, testes and crypt cells
Late responding tissues do NOT express injury for at least 3 months and consist of ________
Slowly dividing cell (RPM cells) like Ong, kidney, liver ,CNS
Hyper fraction is ….
Number of fraction is doubled per day
Time remain same
Total dose is increased
