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Biochem Final > Cell Cycle > Flashcards

Flashcards in Cell Cycle Deck (21)
1

cyclin and CDK of mid G1

cyclin D
CDK4/6

2

cyclin and CDK of late G1

cyclin E
CDK 2

3

cyclin and CDK of S

cyclin A
CDK 2

4

cyclin and CDK of M

cyclin A and cyclin B
CDK 1

5

What signal cascade leads to c-Fos transcription?

MAP kinase

6

What does c-Fos transcribe?

mid-G1:
cyclin D
CDK4/6

7

Which cyclin increases its level throughout G2 and peaks in M phase?

cyclin B

8

Which two CDK complexes are inhibited until DNA replication have completed?

cyclin A/CDK1
cyclin B/CDK1

9

What inhibits cyclin A/CDK 2?

p27KIP1

10

What effect does cyclin D, CDK4/6 have on Rb?

phosphorylates it and releases it from E2F

11

What does E2F do?

promotes the transcription of cyclin E/CDK2 and cyclin A/CDK2

12

When is ATM activated?

when there are double-stranded DNA breaks, caused by irradiation

13

When is ATR activated?

damages from UV light and certain drugs

14

How do ATM and ATR work?

- inhibit phosphatases that normally dephosphorylate CDK complexes which then activate S-phase and mitosis
- also promotes p53 stabilization allowing it to stimulate p21CIP1, an inhibitor of CDK1/2 (no S phase or M phase)

15

What disease is associated with mutation in the gene encoding ATM?

Ataxia Telangiectasia

16

What are PUMA, BID, BAX?

pro-apoptotic proteins

17

What is Bcl-2?

protein that is antiapoptotic and inhibits BAX

18

What is the channel-forming protein of the mitochondrial membrae?

BAX, leads to release of cytochrome c from the mitochonria

19

What stimulates BAX?

PUMA and BID

20

Which is the initiator caspase and which is excecutioner caspase?

caspase-9 (initiator caspase) >> caspase-3 (executioner caspase)

21

How does p53 trigger apoptosis?

by inducing pro-apoptotic proteins (PUMA, BID, BAX)