Cell Cycle Week 5 Holy Flashcards Preview

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Flashcards in Cell Cycle Week 5 Holy Deck (83):
1

Prophase-

first step of M phase or mitosis
- Replicated chromosomes condense
- mitotic spindle assemble between the two centromeres

2

first step of M phase or mitosis
- Replicated chromosomes condense
- mitotic spindle assemble between the two centromeres

Prophase

3

Prometaphase-

second step of mitosis
-nuclear envelope dissociates
-chromosomes attach to spindle microtubules via kinetochores

4

second step of mitosis
-nuclear envelope dissociates
-chromosomes attach to spindle microtubules via kinetochores

Prometaphase

5

Metaphase-

third step of mitosis
-chromosomes aligned at the equator of the cell

6

third step of mitosis
-chromosomes aligned at the equator of the cell

Metaphase

7

Anaphase-

fourth step of mitosis
-sister chromatids separate
-kinetochore microtubules get shorter

8

fourth step of mitosis
-sister chromatids separate
-kinetochore microtubules get shorter

Anaphase

9

Telophase-

fifth step of mitosis
-daughter chromosomes arrive at poles and decondense
-new nuclear envelope begins to form
-contractile ring forms around center of cell in preparation for cytokinesis

10

fifth step of mitosis
-daughter chromosomes arrive at poles and decondense
-new nuclear envelope begins to form
-contractile ring forms around center of cell in preparation for cytokinesis

Telophase

11

Cytokenesis-

contractile ring made of actin and myosin filaments pinches the cell in two creating two daughter cells

12

contractile ring made of actin and myosin filaments pinches the cell in two creating two daughter cells

Cytokenesis

13

Rho proteins-

small G proteins that stimulate actin polymerization; important in formation of contractile ring during telophase and cytokinesis

14

small G proteins that stimulate actin polymerization; important in formation of contractile ring during telophase and cytokinesis

Rho proteins

15

Cohesins-

multi protein complexes that help keep replicated chromosome pairs (daughter chromatids) together until it is time to separate them during, help prevent premature separation and aneuploidy

16

multi protein complexes that help keep replicated chromosome pairs (daughter chromatids) together until it is time to separate them during, help prevent premature separation and aneuploidy

Cohesins

17

Condensins-

multi protein complexes related to cohesins but are involved in the tight packaging of chromatin in mitosis

18

multi protein complexes related to cohesins but are involved in the tight packaging of chromatin in mitosis

Condensins

19

Kinetochore-

complex of protein that assembles on centromeric DNA, made up of centromeric heterochromatin, histone H3 variant called CENP-A. Identifies the location for kinetochore formation.

20

complex of protein that assembles on centromeric DNA, made up of centromeric heterochromatin, histone H3 variant called CENP-A. Identifies the location for kinetochore formation.

Kinetochore

21

CENP-A-

histone H3 variant located on the centromeric heterochromatin; identifies location for assembly of kinetochores

22

histone H3 variant located on the centromeric heterochromatin; identifies location for assembly of kinetochores

CENP-A

23

Kinetochores-

interact with microtubule of the spindle apparatus for separation of daughter chromatids; have signaling function as metaphase checkpoints

24

interact with microtubule of the spindle apparatus for separation of daughter chromatids; have signaling function as metaphase checkpoints

Kinetochores

25

Kinetochore microtubules-

pull daughter chromosomes apart at kinetochores

26

pull daughter chromosomes apart at kinetochores

Kinetochore microtubules

27

Interpolar microtubules-

push chromosomes away from poles to align during formation of metaphase plate; also push against eachother to elongate the spindle in late anaphasae

28

push chromosomes away from poles to align during formation of metaphase plate; also push against eachother to elongate the spindle in late anaphasae

Interpolar microtubules

29

Astral microtubules-

push chromosomes away from poles during formation of metaphase plate

30

push chromosomes away from poles during formation of metaphase plate

Astral microtublues

31

Contractile ring-

formed by contractile fibers of actin and myosin which are controlled by Rho; pinches of two cells during cytokinesis

32

formed by contractile fibers of actin and myosin which are controlled by Rho; pinches of two cells during cytokinesis

Contractile ring

33

CDK-

cyclin dependent kinase, the catalytic subunit of the cell cycle

34

cyclin dependent kinase, the catalytic subunit of the cell cycle

CDK

35

Cyclin-

the regulatory subunit of the cell cycle

36

the regulatory subunit of the cell cycle

Cyclin

37

CKIs-

cyclin dependent kinase inhibitors; two families, CIP/KIP (p21,p27), and Ink4a (p15, p16

38

cyclin dependent kinase inhibitors; two families, CIP/KIP (p21,p27), and Ink4a (p15, p16

CKIs

39

CIP/KIP (p21, p27)-

CKIs that bind cyclin-CDK complexes; upregulated by p53 in response to DNA damage

40

CKIs that bind cyclin-CDK complexes; upregulated by p53 in response to DNA damage

CIP/KIP (p21, p27)

41

Ink4a (p15, p16)-

bind to CDK subunits and prevent cyclin association, upregulated by environmental signaling

42

bind to CDK subunits and prevent cyclin association, upregulated by environmental signaling

Ink4a (p15, p16)

43

Cyclin D, CDK 4 or 6 (which phase?)-

associated with G1

44

Cyclin B, CDK 1 (which phase?)-

associated with M phase

45

CAK-

phosphorylates active site of CDK

46

phosphorylates active site of CDK

CAK

47

Wee1 kinase-

phosphorylates deactivation site of CDK; inhibited by active M-Cdk→positive feedback for continuation of M phase

48

phosphorylates deactivation site of CDK; inhibited by active M-Cdk→positive feedback for continuation of M phase

Wee1 kinase

49

Cdc-25-

removes phosphate added to CDK by Wee1, activates M-Cdk which activates more Cdc-25 through positive feedback

50

removes phosphate added to CDK by Wee1, activates M-Cdk which activates more Cdc-25 through positive feedback

Cdc-25

51

Mitogen growth factor-

activates Ras G protein on plasma membrane to move cell from G0 to G1

52

activates Ras G protein on plasma membrane to move cell from G0 to G1

Mitogen growth factor

53

Ras-

activated by mitogen growth factor, Ras activates MAP kinase cascade

54

activated by mitogen growth factor, activates MAP kinase cascade:

Ras

55

MAP kinase-

Activated by MAP-kinase-kinase-kinase→MAP-kinase-kinase, eventually crosses into nucleus and activates transcription factors by phosphorylating them

56

Rb-

retinal blastoma protein, an important cancer suppressor, acts by binding to EF2 which is a transcription factor in cell division

57

EF2-

transcription factor in cell division which can be inhibited by Rb

58

ORCs, what are they, what phase?

- origin of replication complexes; (G1)

59

Cyclins E and A- what do they do? When do we see them?

produced towards the end of G1, activate CDK2

60

CDK2- function?

recruits preinitiation complex proteins (Cdc6, Cdt1) to ORCs

61

Cdc6- function and fate?

preinitiation complex protein destroyed by Cdk activity after triggering of DNA synthesis so DNA is not replicated more than one in a cycle

62

APC- how's it activated? what are its two main jobs?

Anaphase Promoting Complex; activated by M-Cdk, it inactivates securin which is an inhibitor of separase which promaotes the destruction of cohesin and allows attached chromatids to separate; also destroys CDK activity, ending M phase and initiating cytokenesis

63

Securin- what does it do?

inhibits separase

64

Seperase- what does it do?

promotes destruction of cohesin and subsequently the separation of attached chromatids

65

Cyclin B-

ubiquinated by APC for destruction, abolishes CDK activity ending M phase

66

ubiquinated by APC for destruction, abolishes CDK activity ending M phase

Cyclin B

67

G1 checkpoint requirements-

if extracellular environment is favorable→ G1/S cyclin and Cdk synthesis and progression into S phase

68

if extracellular environment is favorable→ G1/S cyclin and Cdk synthesis and progression into S phase is called:

G1 checkpoint

69

G2/M checkpoint-

makes sure environment is favorable and all DNA is replicated for transition into M phase

70

M phase checkpoint-

ATM/ATR kinases activate if the detect DNA damage; they in turn activate Chk1/Chk2 kinases which phosphorylate p53; p53 is a transcription factor for CKI p21 which blocks Cdk activity and halts cell cycle for attempted DNA repair

71

ATM/ATR kinases activate if the detect DNA damage; they in turn activate Chk1/Chk2 kinases which phosphorylate p53; p53 is a transcription factor for CKI p21 which blocks Cdk activity and halts cell cycle for attempted DNA repair

M phase checkpoint

72

ATM/ATR kinases-

sense DNA damage during M phase checkpoint and activate Chk1/Chk2 kinases if damage exists

73

sense DNA damage during M phase checkpoint and activate Chk1/Chk2 kinases if damage exists

ATM/ATR kinase

74

Chk1/Chk2 kinases-

activated by ATM/ATR when DNA damage is present in M phase; the phosphorylate and activate p53

75

activated by ATM/ATR when DNA damage is present in M phase; the phosphorylate and activate p53:

Chk1/Chk2 kinases

76

What is the function of p53-

critically important protein activated by Chk1/Chk2 and upregulated when DNA damage is present in M phase. p53 functions as a transcription factor for CKI 21 which blocks Cdk activity and halts cell cycle

77

critically important protein activated by Chk1/Chk2 and upregulated when DNA damage is present in M phase. functions as a transcription factor for CKI 21 which blocks Cdk activity and halts cell cycle

p53

78

Spindle checkpoint-

unattached kinetochores activate Bub and MAD2 proteins which inhibit activation of APC thereby blocking anaphase initiation and Cdk destruction; this keeps the cell in pro/metaphase until all kinetochores can bind to microtubules and become aligned in metaphase plate

79

unattached kinetochores activate Bub and MAD2 proteins which inhibit activation of APC thereby blocking anaphase initiation and Cdk destruction; this keeps the cell in pro/metaphase until all kinetochores can bind to microtubules and become aligned in metaphase plate

Spindle checkpoint

80

Bub-

protein activated by unattached kinetochores that inhibits APC and prevents progression into anaphase until all kinetochores are attached to microtubules

81

MAD2-

protein activated by unattached kinetochores that inhibits APC and prevents progression into anaphase until all kinetochores are attached to microtubules

82

Oncogenes-

mutated genes whose presence can stimulate the development of cancer

83

Tumor suppressor genes-

normal genes whose ABSENCE can lead to cancer