Cell Cycle Control and Cancer Flashcards Preview

SSC- Biology of Cancer > Cell Cycle Control and Cancer > Flashcards

Flashcards in Cell Cycle Control and Cancer Deck (49)
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1

What are the phases of the cell cycle? 

M -> G1 -> S -> G2

2

What happens in G1? 

Preparation for DNA replication

3

What happens in S phase?  

DNA replication

4

What happens in G2? 

Preparation for mitosis

 

 

5

Describe the chromosomes in each stage of the cell cycle

  • In G1, 2N (diploid)
  • In S, replication, so 2N -> 4N
  • In G2, 4N (tetraploid)
  • In mitosis, 4N -> 2N

 

6

Describe the transitions between phases in the cell cycle? 

They occur in an orderly fashion 

7

What are the key regulators of the transitions between different stages in the cell cycle? 

Cyclin dependant kinases (CDKs)

8

What are CDKs? 

Seronine/theonine kinases

9

What do serine/theonine kinases do? 

Phosphorylate substrates at SER/THR-PRO-X-LYS/ARG motifs

10

What do the CDK substrates do? 

Promote cell cycle progression

11

When are CDKs active? 

When they are bound by their partners cyclins

12

How do CDK protein levels vary during the cell cycle? 

They are mainly stable 

13

What happens to cyclin levels during the cell cycle? 

They rise and fall 

14

What is the result of the rising and falling of cyclin levels during the progression of the cell cycle? 

Activation of CDK oscillates 

15

Does CDK or cyclin dictate the progression of the cell cycle? 

Cyclin, as its levels are rising and falling

16

What CDKs operate during G1? 

CDK4-6

17

What cyclins are involved in the G1 phase of the cell cycle? 

Cyclin D1, D2, and D3

18

What CDKs are involved in the G1/S phase of the cell cycle? 

CDK2

19

What cyclins are involved in the G1/S phases of the cell cycle? 

Cyclin E1, E2

20

What CDKs are involved in the S phase of the cell cycle? 

CDK2

21

What cyclins are involved in the S phase of the cell cycle? 

Cyclin A1, A2

22

What CDKs are involved in the M phase of the cell cycle?

CDK1

23

What cyclins are involved in the M phase of the cell cycle?

Cyclin B1

24

What cyclins and CDKs are essential for entry into G1?

CyclinD/CDK4-6

25

What cyclins and CDKs regulate G1 to S progression? 

CyclinE/CDK2

26

What cyclins and CDKs are required during S and G2 phases

CyclinA/CDK2

27

What do cyclinA/CDK2 do during S and G2 phases?

Triggers DNA polymerase activity

28

What cyclins and CDKs promote entry into mitosis?

CyclinB/CDK1

 

 

29

What is RB? 

A tumour supressor gene

30

How does RB act as a tumour suppressor gene? 

Rb binds to E2F, which inhibits it from transcribing its S-phase genes