9.9 Cell Cycle Flashcards Preview

Foundations Exam 3 > 9.9 Cell Cycle > Flashcards

Flashcards in 9.9 Cell Cycle Deck (32):
1

what does the cell do in G1 phase?

it gathers nutrients and energy. Lives and prepares

2

what does the cell do in the S phase?

it commits to duplication and division. DNA/organelle replication

3

what does the cell do in the G2 phase?

it checks and fixes DNA
DNA repair

4

what does the cell do in M phase?

divide

5

what are the three locations of the major cell cycle checkpoints?

G1/S transition
G2/M transition
metaphase/anaphase transition

6

what causes transition between G1 to S phase?

increase in CycE-Cdk2 levels

7

CycE-Cdk2 increase levels of what other cyclin?

CycA

8

CycA degrades _____ (what cyclin)

CycE

9

what does CycA do?

it induces DNA replication in S phase

10

CycB (inactivated) increases and is maximal before ____ phase. It degrades Cyc___.

M phase
CycA

11

CyB is regulated by phosphorylation by two enzymes: ______ and ______. Which inhibits and which activates?

CAK - activated
Wee - inhibits

12

to activate CycB, the inhibitory phosphate needs to be removed by _______.

Cdc25

13

what activated Cdc25 to dephosporylate the inhibitory phosphate on CycB?

complete and accurate DNA replication

14

once the inactivating inhibitory phosphate is removed from CycB, what phase transition can happen?

G2 --> M phase

15

what is the "anaphase wait" signal?

all kinetochores are attached with a microtubule and ready to split

16

Wee1 inhibits what?

CycB-Cdk1

17

once anaphase is reached, what is expressed? What do they do?

APCs are expressed, they degrade CycB and CycA

18

what regulates CDKs? (4)

1. cyclin changes (either increase in expression through TFs or degradation such as APCs)
2. Phosphorylation (Wee, CAK)
3. CKIs (CDK inhibitors) in G1

19

what are CKIs? (p21, p27, etc)

inhibitors of CDK

20

what is pRB? Is it an oncogene or a tumor suppressor gene?

it is a protein that connects to E2F (on oncogene) and suppresses its activity.

21

pRB suppresses ______, which is an oncogene.

E2F

22

E2F goes to the nucleus and acts as a TF, expressing ________, inducing which transition?

CycE
G1/S transition

23

what oncogene acts as a TF that induces CycE expression, inducing transition from G1 to S phase? what suppresses this?

E2F
pRB

24

an oncogenes normal activity is to ______ the cell cycle.

progress

25

a tumor suppressor gene functions to ______ the cell cycle

slow

26

RB, p53, p16 (CKIs) are examples of:

tumor supressor genes

27

myc, ras, raf, cdc25, Cdks, cyclins, EGFR are examples of:

oncogenes

28

_____/_____ detect DNA damage

ATM/ATRs

29

ATM/ATRs can activate _____ (a CKI) which assures cells have time to repair damage or if the damage is too extensive, initiate apoptosis

p53

30

p21 inhibits ____s

CDKs

31

reverse in inhibition of ______ allows the cell to progress to M phase from G2 phase

CycB

32

in response to mitogen, cyc____-Cdk phosphorylates E2F, causing it to express cyclin E and A

D