Cell Cycle

Question 1

G1

Answer 1

growth phase before DNA synthesis

Question 2

G2

Answer 2

second growth period that’s before cell division

Question 3

M phase

Answer 3

cell division

Question 4

G1/S checkpoint

Answer 4

start or restriction point. cell tells if conditions are faborable for division

Question 5

G2/M chekcpoint

Answer 5

make sure all DNA has been replicated and the environment is still favorable for division

Question 6

metaphase/anaphase transition point

Answer 6

all chromosomes are evalutated to ensure that they are attached to mitotic spindle

Question 7

DNA damage checkpoint

Answer 7

functions throughout the cell cycle, detects damage ti DBA

Question 8

CDKs

Answer 8

enzymes that help progress through the cell cycle

Question 9

M phase Cyclin/CDK complexs

Answer 9

Cyclin A/CDK1

Cyclin B/CDK1

Question 10

Mid G1 cyclin/CDK complexes

Answer 10

cyclin D/CDK4

Cyclin D/ CDK6

Question 11

late G1 cyclin.CDK complexes

Answer 11

Cyclin E/CDK2

Question 12

S cylin CDK compelx

Answer 12

cyclin A/CDK2

Question 13

how are cyclins degraded

Answer 13

ubiquitin-dependent proteolysis

Question 14

how is cyclin B ubiquinited

Answer 14

anaphase promoting complex

Question 15

mitogenic signals

Answer 15

tissue-specific growth factors

required to stimulate cell growth and dvision

Question 16

what phase are most differentiated cell in

Answer 16

G0

Question 17

in general what do interactions between cell and ECM do

Answer 17

promote cell division

Question 18

in general what do interactions between neighboring cells do

Answer 18

inhibit cell division

Question 19

contract inhibition

Answer 19

two neighboring cells contact each other and inhibit cell dibision

Question 20

early-response genes

Answer 20

genes transcribed within a few minutes of addition of gorwth factor to a cell in G0

Question 21

what is a key player amoung the early-response genes

Answer 21

transcription factor c-FOs

Question 22

function of c-fos

Answer 22

stimulate transcripition of delayed response genes

Question 23

what do the recceptors for gorwth facotors contain

Answer 23

intrinsic tyrosine kinase activitry

Question 24

what does ligand binding to receptors for growth factors tirgger

Answer 24

recpetor dimerixation, autophosphorylation of tyrosine residues within the recpetor

Question 25

how do most growth factors stimulate transcription of the gene encording c-fos

Answer 25

MAP kinase cascade

Question 26

how does MAP kinase cascade start

Answer 26

GRB2 binds to phosphotyrosine residues within the activated receptor.

Question 27

what happesn after GRB2 bindws

Answer 27

binds to SOs, brining it into the cell membrane

Question 28

what happens when Sos is in the cell membrane

Answer 28

activates Ras

Question 29

what does active Ras do

Answer 29

activates Raf

Question 30

what does activated Raf do

Answer 30

activate MAP kinase kinase

Question 31

what does MAP kinase kinase do

Answer 31

activate MAP kinase

Question 32

what does MAP kinase do

Answer 32

stimulate c-Fos transcirption

Question 33

what happens after the cell passes the restrition point

Answer 33

it can go through the S, G2, M phases of cell cycle in the absense of growth factors

Question 34

what is the key target for cycline D-CDK4/6 compelx

Answer 34

retinoblastoma protein (RB)

Question 35

fucntion of Rb

Answer 35

binds to E2F proteins

Question 36

functino of E2F proteins

Answer 36

transcription factors, stimulate transciriiption of cyclin E and cyclin A and CDK2.

Question 37

when E2F is bound to Rb how does it function

Answer 37

as a repressor instead of activator

Question 38

when cyclin E-CDK2 is present, Rb phosporylation because what

Answer 38

independt of cyclin D-CDK4.6

Question 39

INK4

Answer 39

growth inhibitory factors taht compete with cyclin D for binding to CDK4/6

Question 40

p27KIP1

Answer 40

small protein that forms a compelx with cyclin A-CDK2,

Question 41

what is the most important driver of events leading up to mitosis

Answer 41

CDK1

Question 42

when is cyclin A present

Answer 42

from early S phase

Question 43

when does cyclin B synthesisi ahppen

Answer 43

late in S phase, incrases through G2

Question 44

when is the peak levle of cyclin B

Answer 44

metaphase of mitosis

Question 45

the cyclin/CDK1 complexes are held in an inactivate state until when

Answer 45

DNA replication is completed

Question 46

what triggers activation of anaphase promoting complex

Answer 46

appropriate arrangement of chromosomes and attachment to mitotic spindle in metaphase

Question 47

how does protein dephosphorylation affect the effects of cyclin/CDK1 actiity

Answer 47

reverse

Question 48

ATM

Answer 48

detects replication forks, activates another kinase that preents dephosphorylation and activation of cyclin/CDK1 complexes needed to enter mitosis

Question 49

when is ATM active

Answer 49

as long as replication forks are present

Question 50

what is anaphase depend ont

Answer 50

association of all chromosomes with the spindle

Question 51

what activates ATR

Answer 51

DNA damage caused by UV light and certain drugs

Question 52

activation of ATM/ATR does what

Answer 52

inhbiits phosphateaases tha tnormally dephosphorylate and activate cycline/CDK2 and cyclin/CDK1 compelxes

Question 53

activation of ATM/ATR results in phosphorylation of waht protein

Answer 53

p53

Question 54

p53

Answer 54

transcritpion factor that is normally unsable

Question 55

importnat traget of p53`

Answer 55

p21CIP1.

Question 56

p21CIP1

Answer 56

inhbitior of cyclin-dpeendent kinases.

Question 57

what specifically does p21CIP1 inhibit

Answer 57

cylin/CDK1 and cycline/CDK2

Question 58

what caues ataxia-telangiectasisa

Answer 58

muations in protein kianse ATM

Question 59

symptoms of ataxia telangeita

Answer 59

susceptivle to infection (especially chronic lung) | increases risk for leukemia, lymphoma, sensitive to radiation exposure

Question 60

what produces TNF

Answer 60

macropahses

Question 61

waht produces Fas ligands

Answer 61

natural killer cells, cytotoxic T lymphocytes

Question 62

proapoptotic proteins

Answer 62

PUMA, BID, BAX (BCL-2 family)

Question 63

BCL-2

Answer 63

antiapoptotic protein. inhibits BAX

Question 64

BAX

Answer 64

can form a channel in the mitochondrial outer membran

Question 65

function of PUMA and BID

Answer 65

stimulate BAX

Question 66

when stimualtes BAX allows the release of waht

Answer 66

cytochrome c

Question 67

what happens when cytochorome c enters cytoplasm

Answer 67

binds to Apaf-1

Question 68

what happens after cytochrome c binds to Apaf-1

Answer 68

makes apoptosomes

Question 69

function of apoptosome

Answer 69

recruite, activate caspase 9

Question 70

functino of caspase 9

Answer 70

activates caspase 3 (excustioner caspases)