Brainscape's Knowledge GenomeTM

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


See full index

Cellular Pathology > Cellular growth regulation > Flashcards

Cellular growth regulation Flashcards

1
Q

What is the difference between hyperplasia and hypertrophy?

A

HyperPlasia = increase in cell numbers
Hint: P = Plenty

Hypertrophy = increase in cell size

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

What is apoptosis?

A

A coordinated programme of cell dismantling followed by phagocytosis

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

Give examples of where apoptosis can occur during normal development

A
  • Separation of the digits
  • Involution
  • Immune system development
  • Nervous system development
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is involution?

A

For example it is when the uterus returning to normal size post pregnancy

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

Apart from during normal development, what else can trigger apoptosis to occur?

A

Can occur in response to DNA damage and viral infection

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

What 3 roles do GF, Cytokines and IL play? Give specific examples

A
  • Stimulate proliferation and maintain survival (mitogens)
  • Stimulate differentiation and inhibit proliferation (TGF-B)
  • Induce apoptosis (TNF-A)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Give examples of mitogens

A
  • EGF
  • FGF
  • IL2 & IL4
  • NGF
  • PDGF (platelet derived growth factor)
  • IGF1 (insulin like growth factor)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the proteins that stimulate proliferation called?

A

Mitogens

These are required for the survival of the cells

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

Function of TGF-B (transforming growth factor beta)

A
  1. Stimulates differentiation

2. Inhibits proliferation

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

Function of TNF-A (tumour necrosis factor alpha)

A

Induces apoptosis

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

Name and describe the 3 methods of signalling

A

Paracrine:
Produced locally to stimulate a DIFFERENT CELL TYPE with the appropriate cell surface receptor

Autocrine:
Produced by a cell that acts on the SAME CELL TYPE with the appropriate cell surface receptor

Endocrine:
Released to act on distant cells

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

Outline the stages of the cell cycle

A
  • The cell cycle consists of four stages: G1, S, G2, and M.
  • G1 and G2 are ‘gap’ phases in which the cell grows and prepares to divide.
  • S in the synthesis phase in which the chromosomes (DNA) are copied (replicated).
  • M is the mitotic phase in which the cell physically divides into two daughter cells.
  • Most cells are NOT actively dividing. These cells are in a resting state (G0)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens during M phase?

A

Mitosis in normal cells produces TWO cells with identical genetic content.

The daughter cells can:
• Re-enter the cell cycle
• Withdraws from the cell cycle (arrests). This cell is in the G0 phase of the cell cycle and is called the Quiescent cells. These cells can then take 2 different paths:
1. These cells can re-enter the cell cycle and start dividing if stimulated by mitogen (growth factor)
OR
2. Receive TGF-B which will induce differentiation of the cells. These cells can then renew the cells removed by cell shedding/apoptosis .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q 
2N = how many chromosomes?
4N = how many chromosomes?
A 
2N = 23 chromosomes 
4N = 46 chromosomes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the 2 fates of a daughter cell arrested in mitosis (G0)?

A
  1. These cells can re-enter the cell cycle and start dividing if stimulated by mitogen (growth factor)
    OR
  2. Receive TGF-B which will induce differentiation of the cells. These cells can then be used to renew the cells removed by cell shedding/apoptosis.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a fluorescent DNA stain and how is it used?

A

Use a fluorescent DNA stain to treat the cells. This will bind to DNA. This can then be used to measure the amount of DNA present.

17
Q

FLUORESCENT DNA STAIN

During a LOW rate of cell division, what phase of the cell cycle would the majority of the cells be found in?

A

majority found in G1 (60%)

18
Q

FLUORESCENT DNA STAIN

During a HIGH rate of cell division, what phase of the cell cycle would the majority of the cells be found in?

(in comparison to a low rate of cell division, what would the shift in % be?)

A

COMPARED TO LOW RATE OF CELL DIVISION (where 60% of cells were found in G1) there would be:
less cells found in G1 phase
AND
more cells found in S/G2/M phase

this is because during high cell division, more of the cells will be progressing through the cell cycle

19
Q

As a recap, go through DNA replication

A

1) DNA is replicated semi conservatively (daughter cells inherit one parental and one new strand).
2) New DNA is synthesized in the 5’ to 3’ direction from deoxynucleotide triphosphate precursors at a replication fork by a multienzyme complex (a replication machine).
3) Fidelity is determined by base pairing (A=T, G≡C) and presence of a proof reading enzyme in DNA polymerase.
4) Synthesis of the new DNA strand uses an RNA primer and occurs continuously on the leading strand and discontinuously on the trailing strand (giving rise to Okazaki fragments, which are ligated together after removal of the RNA primer).

20
Q

Describe the 4 stages of mitosis in terms of what changes can be seen within the cell under a microscope

A

1) PROPHASE:
- Nucleus becomes less definite
- Microtubular spindle apparatus assembles
- Centrioles (yellow) migrate to poles

PROMETAPHASE:

  • Nuclear membrane breaks down
  • Kinetochores attach to spindle in nuclear region

2) METAPHASE:
- Chromosomes (blue) align in equatorial plane

3) ANAPHASE:
- Chromatids separate and migrate to opposite poles

4) TELOPHASE:
- Daughter nuclei form

Another phase that is considered is CYTOKINESIS:

  • Division of cytoplasm
  • Chromosomes decondense
21
Q

Name 2 drugs that can act during the S phase of mitosis and describe what it does

A

5-fluorouracil (an analogue of thymidine BLOCKS thymidylate synthase activity)
No thymidine = no DNA replication = arrests mitosis in S phase

Bromodeoxyuridine aka BrdU (an analogue that can be incorporated into DNA, it is detected by antibodies to identify the cells that have passed through the S phase)

22
Q

what is 5-fluorouracil

A

(an analogue of thymidine BLOCKS thymidylate synthase activity)

No thymidine = no DNA replication = arrests mitosis in S phase

23
Q

what is Bromodeoxyuridine aka BrdU

A

(an analogue that can be incorporated into DNA, it is detected by antibodies to identify the cells that have passed through the S phase)

24
Q

What is tamoxifen and its role in breast cancer?

A

Oestrogen is required for the breast cancer cells to grow. Tamoxifen is an antagonist of oestrogen. Cells can be treated with tamoxifen to prevent growth of breast cancer cells. You can check if the growth of the cells has stopped using BrdU which will bind to any breast cancer cells that have progressed through the S phase. After tamoxifen treatment the amount of BrdU detected should decrease.

Tamoxifen = less BrdU detected = indicates less breast cancer cells progressing through S phase

25
Q

Name 2 drugs that can act during the M phase of mitosis and describe what it does

A

Colchicine
• Stabilises free tubulin = preventing microtubule polymerisation = arrests cells in mitosis therefore they cannot divide
• This can be used in karyotype analysis

Vinca alkaloids (similar action to colchicine)
Paclitaxel (taxol)
• Stabilises microtubules 
• Prevents destabilisation 
This means the cells cannot separate
26
Q

Name 2 drugs that can act during the M phase of mitosis and describe what it does

A

Colchicine
• Stabilises free tubulin = preventing microtubule polymerisation = arrests cells in mitosis therefore they cannot divide
• This can be used in karyotype analysis

Vinca alkaloids (similar action to colchicine)

Paclitaxel (taxol)
• Stabilises microtubules
• Prevents destabilisation
This means the cells cannot separate

27
Q

what is the role of the drug colchicine during the M phase

A

• Stabilises free tubulin = preventing microtubule polymerisation = arrests cells in mitosis therefore they cannot divide

This can be used in karyotype analysis

28
Q

what is the role of vinca alkaloids during the M phase

A

similar action to colchicine

arrests cells in mitosis therefore they cannot divide

29
Q

Name 4 drugs used in the treatment of cancer

A
  1. 5-flurouracil
    1. Paclitaxel
    2. Vinca alkaloids
    3. Tamoxifen

These all act to prevent cell division/growth of tumours

30
Q

G1 and G2 checkpoints can detect DNA damage. If DNA damage is detected, what 2 things can happen?

A

Triggers cell cycle arrest to try and attempt to repair the DNA and IF repaired it can re-enter the cell cycle

OR

IF DNA repair CANNOT occur/is impossible then apoptosis occurs

31
Q

G1 and G2 checkpoints can detect DNA damage. This then triggers cell cycle arrest. What 2 things can be used to trigger cell cycle arrest?

A

Cyclin dependent kinase inhibitors

CHEK2

32
Q

G1 and G2 checkpoints can detect DNA damage. This then triggers cell cycle arrest to attempt DNA repair. What is used to attempt repair of the DNA?

A

nucleotide or base excision enzymes

mismatch repair enzymes

33
Q

G1 and G2 checkpoints can detect DNA damage. This then triggers cell cycle arrest to try to repair the DNA. However, if the DNA cannot be repaired, apoptosis is triggered. What is involved in the apoptosis of the damaged irreparable cells

A

BCL2 family

Caspases

34
Q

What are the controls involved in the cell cycle checkpoints? What is involved in them and what are their roles?

A

Controls (involving specific protein kinases and phosphatases) ensure the strict alternation of mitosis and DNA replication

35
Q

What are the 3 cell cycle checkpoints and what is the purpose of each of them?

A 
1. G1 checkpoint checks for:
	• DNA damage 
	• Cell size 
	• Metabolites/nutrient store 
	2. G2 checkpoint checks for:
	• Complete DNA replication 
	• No DNA damage 
	3. M checkpoint checks for:
• Chromosomes aligned on the spindle
36
Q

At what point in the cell cycle are the cells responsive to growth factors?

A

G1 phase is where the cells are responsive to growth factors
This is the main site of control for cell growth

37
Q

What is progression through the cell cycle controlled by?

A

Cyclin-dependent kinase activity

Cellular Pathology (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions