Week 2

Question 1

what is G1 phase

Answer 1

synthesis of RNA and
proteins, preparation for S phase

Question 2

what is s phase

Answer 2

DNA synthesis and
chromosome replication

Question 3

what is G2 phase

Answer 3

continued growth,
preparation for M phase

Question 4

what is M phase

Answer 4

mitosis occurs, with
segregation of chromosomes into daughter cells

Question 5

what is G0 phase

Answer 5

exit from the cell cycle; state of being for all differentiated cells in the body

Question 6

what are cyclins

Answer 6

the regulatory subunits
that control cell-cycle events

Question 7

what are CDKs

Answer 7

catalytic subunit;
phosphorylate proteins
associated with a particular Cyclin-CDK complex

Question 8

what is a kinase

Answer 8

catalyze the transfer of a
phosphate from ATP to a OH group (Serine Threonine, or Tyrosine side chains) on a target protein

Question 9

what is a phosphatase

Answer 9

catalyze the
dephosphorylation of the protein

Question 10

what is a CDKI

Answer 10

inhibitor of CDK

Question 11

What is inhibitory phosphorylation

Answer 11

CDK is phosphorylated and becomes inactive even with CDK cyclin complex

Question 12

what is a inhibitory kinase for CDK

Answer 12

wee 1

Question 13

what is a excitatory phosphatase

Answer 13

cdc 25

Question 14

EGFR pathway activates what transcription factor

Answer 14

Myc

Question 15

what gene does myc transcribe

Answer 15

cyclin D gene

Question 16

cyclin D-CDK phosphorylates and inactivates what protein

Answer 16

Rb

Question 17

Once Rb is phosphorylated what happens after

Answer 17

It releases E2F and allows it to transcribe S-phase genes

Question 18

what is the restriction point

Answer 18

G1/S phase

Question 19

What is regulation of the restriction point

Answer 19

Growth factors must be
continually provided at
high levels to accumulate
enough Cyclin D to drive
past the restriction point

Question 20

what are some tumor suppressors

Answer 20

Rb, p53, CDKis

Question 21

what is Knudsons’s two hit hypothesis

Answer 21

tumor suppressor genes function like recessive genes

Question 22

what is dna damage regulated by

Answer 22

p53 and ATM

Question 23

how is unreplicated dna controlled

Answer 23

ATR

Question 24

what is ATM

Answer 24

kinase that helps to repair double DNA strand repair, tumor suppressor, activates p53

Question 25

what is ataxia telangiectasia

Answer 25

atm is mutated, autosomal recessive disorder

Question 26

what is ATR

Answer 26

kinase activated by DNA damage and single stranded DNA, leads to activation of p53

Question 27

what is p53

Answer 27

transcription factor that acts as a tetramer, 4 molecules together to bind dna

Question 28

how is p53 regualted

Answer 28

MDM2, a ubiquitin ligase, targets p53 for degradation, in dna damage MDM2 is inhibited and p53 increases

Question 29

what genes do p53 transcribe

Answer 29

CDKis, causes halt in cell cycle and replication

Question 30

what is Li-Fraumeni Syndrome

Answer 30

autosomal dominant, one p53 allele is mutated decreased ability to bind dna

Question 31

what is TGFBR

Answer 31

serine/theronine kinase, heterodimer, some of its mediators inhibit growth of epithelial cells (depends on the cell)

Question 32

Where is TGFBR stored and released

Answer 32

released from wbc and stored latent in the ECM

Question 33

what is the 1st step in the TGFBR pathway

Answer 33

ligand binds to receptor and receptor dimerizes

Question 34

what is the 2nd step in the TGFBR pathway

Answer 34

receptor phosphorylates the SMAD transcription factors and the dimerize

Question 35

what is the 3rd step in the TGFBR pathway

Answer 35

SMADs expose their nuclear localization signal and go tot the nucleus

Question 36

what is the 4th step in the TGFBR pathway

Answer 36

SMAD's interact with transcriptional cofactors to regulate transcription (depends on cell)