3 lecture 2 Flashcards

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1
Q

do cells make mistakes

A

yep

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2
Q

what is an example of a mistake a cell makes

A

lagging chromosomes

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3
Q

why do chromosomes lag behind

A

some just take longer than others to separate

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4
Q

what is a euploid cell

A

have correct number of chromosomes

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5
Q

do lagging chromosomes cause problems

A

they can

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6
Q

how do lagging chromosomes cause problems

A

the lagging chromosome will be trapped in the spindles mid zone during anaphase
the trapped chromosome will be trapped and damaged in the process of the cell splitting

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7
Q

is it quick to fix mistakes int he cell

A

nope

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8
Q

is cell division a controlled process

A

Cell division is a tightly controlled process

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9
Q

what ensures that there are no mistakes in a cell

A

Proteins survey the condition of the cell at each step

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10
Q

If a mistake is detected, what happens

A

normal cells halt at checkpoints and make repairs

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11
Q

what must happen in order for cells to proceed with division

A

Cell must pass the survey to proceed with cell division

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12
Q

what are the 3 major checkpoints

A

3 major checkpoints: G1,G2, and metaphase

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13
Q

do the checkpoints have a fixed amount of time that they go on for

A

checkpoints monitor the processes and impose a delay as needed

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14
Q

what is checked in the g1 checkpoint

A

is cell division necessary
are growth factors present
is the cell large enough
are suficient nutrients available

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15
Q

what is checked in the s checkpoint

A

nothing really

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16
Q

what is checked in the g2 checkpoint

A

what DNA replicated correctly

is the cell large enough

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17
Q

what is checked in the metaphase checkpoint

A

are all the chromosomes attached to microtubules

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18
Q

what happens if the daughter cells are not the exact same size

A

daughter cells may not be exactly the same size, so the smaller one will take longer to reach the cell size threshold and and will be in G1 phase for longer

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19
Q

what does Mitosis do

A

produces two genetically-identical nuclei

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20
Q

what happens if even one chromosome is wrong

A

chromosome attachment is monitored if even one is wrong, anaphase is delayed

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21
Q

can mistakes happen in healthy cells

A

yep

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22
Q

what is disease, if mistakes also happen in healthy cells

A

it is the failure to detect and correct mistakes that lead to disease

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23
Q

what are the 2 origins of cancer

A

oncogenes

tumour suppressors

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24
Q

what is oncogene

A

losing control

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25
Q

what are tumour suppressors

A

losing a checkpoint

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26
Q

cancer is the result of what

A

defects in checkpoint or repair systems

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27
Q

what typically are the ones that turn into oncogenes

A

growth factors

28
Q

what are growth factors

A

stimulate cells to divide

29
Q

how do growth factors work

A

Growth factors bind to receptors to trigger a response from a cell

30
Q

what is a Mutation:

A

a change in the sequence of DNA

31
Q

Changes to DNA can change what

A

Changes to DNA can change the structure and function of the protein coded by the DNA

32
Q

what causes mutations

A

Mutations may be inherited or caused by carcinogens

33
Q

what are Proto-oncogenes

A

genes that code for cell cycle control proteins

34
Q

what happens When proto-oncogenes mutate

A

When proto-oncogenes mutate, they become oncogenes

Their proteins no longer properly regulate cell division
They usually overstimulate cell division

35
Q

what are the 3 paths to cancer (oncogenes)

A

1– translocation or transportation: gene move to new locus, under new controls… this leads to normal growth-stimulating protein in excess
2– gene amplification: multiple copies of the genes…. normal growth-stimulating protein in excess
3– point mutation within the gene: oncogene: hyperactive or degradation-resistant protein: excess growth

36
Q

what are Tumor suppressor genes:

A

genes for proteins that stop cell division if conditions are not favorable

37
Q

what happens when Tumor suppressor genes are mutated

A

When mutated, can allow cells to override checkpoints

38
Q

what happens when oncogene and tumour suppressor mutations occur

A

= bad

Depending on the number of mutations and whether the tumor suppressor protein is functional will determine whether it is a benign or malignant tumor that is formed

39
Q

what is the Multiple hit model

A

process of cancer development requires multiple mutations

40
Q

what is the 2 hit hypothesis

A

Some mutations may be inherited (familial risk)

Most are probably acquired during a person’s lifetime

41
Q

progression from a benign tumor to cancer requires many mutations and results in what

A

a constellation of defects

42
Q

what are the 2 types of results that can happen from mutation (on a cellular function level)

A

Loss of contact inhibition:

Loss of anchorage dependence:

43
Q

what is Loss of contact inhibition

A

cells will now pile up on each other

44
Q

what is Loss of anchorage dependence

A

enables a cancer cell to move to another location

45
Q

is Loss of contact inhibition definitely cancerous

A

can be part of benign

46
Q

is Loss of anchorage dependence definitely cancerous

A

big indicator of cancerous

47
Q

what is Immortalized:

A

cells no longer have a fixed number of cell divisions due to an enzyme called telomerase

48
Q

what is the difference between malignant and benign tumours

A

malignant– (cancer) cells invade neighbouring tissues, enter blood vessels, and metastasize to different sites
benign– (not cancer) tumour cells grow only locally and cannot spread by invasion or metastasis

49
Q

give a detailed process of metastasis

A
primary tumour
vascularization
detachment
intravasion
circulating tumour cell
adhesion to blood vessel wall
extravasation
growth of secondary tumour
50
Q

animal cells need what to divide

A

telomeres

51
Q

what is the the relationship between telomere length and age

A

the relationship between telomere length and age is not understood

52
Q

Early detection increases odds of survival true or false

A

true

53
Q

is there just one way to detect cancer

A

There are different detection methods for different cancers

54
Q

what is a Biomarker

A

Some cancers produce increased amount of a characteristic protein (non-functional or altered)

55
Q

what is Biopsy

A

surgical removal of cells or fluid for analysis

56
Q

what are the ways to detect cancer

A

Biomarker

biopsy

57
Q

what are the types of biopsyq

A

Needle biopsy:

Laparascope:

58
Q

what is Needle biopsy:

A

removal is made using a needle

59
Q

what is Laparascope:

A

surgical instrument with a light, camera, and small scalpel

60
Q

what are the types of cancer treatment

A

Chemotherapy:

Radiation therapy:

61
Q

what is chemotherapy

A

drugs that selectively kill dividing cells
Combination of different drugs used (“cocktail”)
Interrupt cell division in different ways
Helps prevent resistance to the drugs from arising
Normal dividing cells are also killed (hair follicles, bone marrow, stomach lining)

62
Q

what is radiation

A

use of high-energy particles to destroy cancer cells
Damages their DNA so they can’t continue to divide or grow
Usually used on cancers close to the surface Typically performed after surgical removal of tumor

63
Q

If a person remains cancer free after treatment for 5 years they are in remission and after 10 years they are considered to be cured
true or false

A

true

64
Q

how tough is a tardigrade

A

the water bear is almost impossible to kill
when dehydrated can go more than than 10 years without food or water;
when hydrated it:
can survive unprotected in space;
extreme temperatures
• A few minutes at 151 °C (304 °F)
• A few days at −200 °C (−328 °F)
• A few minutes at −272 °C (~1 K, −458 °F)
can withstand vaccum and high pressure (>1,200 x);
can survive ionizing and UV radiation that would kill a human

65
Q

why are they so tough (the tardigrade)

A

its complicated…

extra copies of genes required to repair DNA
loss of genes that stimulate autophagy in the presence of stress
tardigrade-specific genes that protect DNA (Dsup)
many tardigrade genes function still unknown