Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PoD topics > Tumours 4 > Flashcards

Tumours 4 Flashcards

1
Q

What is the order of the cell cycle starting from M?

A

M, G1, S, G2 and back to M

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

Which parts of the cell cycle make up the interphase (longest part)?

A

G1, S, G2

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

What is G0?

A

Resting mode of the cell

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

what process in the cell cycle ensures each cell receives a full chromosome complement and does not have any mutations?

A

Quality control check

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

What can be the outcomes if there is a problem with the cell and it doesn’t pass the quality control? (2)

A
  1. DNA is fixed/ repaired

2. apoptosis occurs

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

what are some external factors which affect cell cycle control?

A
  • hormones
  • growth factors
  • cytokines
  • stroma (connective tissue cells)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What intrinsic factors can affect cell cycle control?

A
  • critical checkpoints (restriction point)

- after restriction point, progression becomes autonomous (cell controls itself)

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

what occurs in G1 phase? (2)

A
  • cell increases in size

- G1 checkpoint ensures everything is ready for DNA synthesis

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

what occurs in S phase?

A

DNA replication occurs

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

What occurs in G2 phase? (2)

A
  • cell continues to grow

- checkpoint ensures that everything is ready to enter the M phase

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

what chemicals are present at checkpoints?

A

cyclically active and inactive enzymes

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

What are catalytic subunits activated by?

A

Regulatory subunits

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

What are catalytic subunits called?

A

Cyclin-dependent kinases (CDKs)

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

what are regulatory sub-units called?

A

Cyclins

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

What is the active enzyme complex called in the cell cycle?

A

CDK/cyclin complex

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

What do active CDK/cyclin complexes do?

A

Phosphorylate proteins (which results in activation or inactivation of substrates)

17
Q

What form are CDKs constitutively expressed in?

A

Inactive form

18
Q

What does CDK need to become activated?

A

Cyclins

19
Q

what kind of phosphorylation occurs at pRb?

A

hypophosphorylation

20
Q

what happens to phosphorylation as cell progresses through the cycle?

A

increases

21
Q

what phosphorylates pRb?

A

active cyclin D/CDK complexes

22
Q

What happens to the cell cycle when it stops? (in terms of pRb and E2F)

A
  • pRb is active (hypophosphorylated)

- inactive E2F

23
Q

What happens to the cell cycle when it goes ahead? (in terms of pRb and E2F)

A
  • inactive pRb ( phosphorylated)

- active E2F

24
Q

What activates vital target genes in the cell cycle?

A

free E2F transcription factor

25
Q

What is the E2F factor?

A

Stimulator of cell cycle entry

26
Q

What does active pRb do to the cell cycle?

A

Puts a brake on the cell cycle (stops it)

27
Q

What 3 factors are affected which cause a cell to lose control of its proliferation?

A
  1. cell division
  2. apoptosis
  3. DNA repair
28
Q

What 3 non-lethal genetic damage can cause carcinogenesis?

A
  1. chemicals
  2. radiation
  3. oncogenic viruses
29
Q

what does chemical carcinogenesis cause in DNA on a molecular level?

A

purine and pyrimidine bases in DNA are critically damaged by various oxidising and alkylating agents

30
Q

What is formed as a result of chemical carcinogenesis on particular chromosome sites?

A

Adduct formation (DNA adducts)

31
Q

What does radiation carcinogenesis cause in DNA on a molecules level?

A

purine and pyrimidine bases in DNA are critical cellular targets for radiation damage

32
Q

What are 3 examples of harmful radiation?

A
  1. UV present in sunlight
  2. X rays
  3. gamma radiation
33
Q

what are the 2 regulatory pathways which are frequently disrupted?

A
  1. cyclin D-pRB-E2F pathway (absent or inactive pRb releases cell cycle brake and E2F is activated which causes proliferation)
  2. p.53 pathway (which is a tumour suppressor)
34
Q

What does p.53 do?

A

tumour suppressor

35
Q

What are the 4 genes which often have mutations causing cancers?

A
  1. Rb
  2. CDK4
  3. cyclin D
  4. p.16 (tumour suppressor gene)
36
Q

What happens to the level of p.53 in damaged cells?

A

increases

37
Q

Why is p.53 increased in damaged cells?

A
  • facilitates DNA repair

- induces cell cycle arrest at G1 and apoptosis

38
Q

What happens if there is a mutation to p.53 gene?

A
  • cells do not arrest at G1 or repair damaged DNA

- cells proliferate and form malignant neoplasm (uncontrollable cell division)

PoD topics (34 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions