Lecture 15

Question 1

What is necessary for initiation of replication?

Answer 1

Licensing factor

Question 2

When is licensing factor present?

Answer 2

Prior to replication, but then it’s removed, inactivated or destroyed after

Question 3

When is a new replication cycle possible?

Answer 3

When licensing factor re enters the nucleus after mitosis (the nuclear envelope must first break down)

Question 4

What 2 things make up licensing factor?

Answer 4

CDC 6 and MCM 2, 3, and 5

Question 5

Explain the process of Licensing factor step 1

Answer 5

ORC sits on ARS early in G1

Question 6

LF step 2

Answer 6

CDC6 associates with the ORC

Question 7

LF step 3 in late G1

Answer 7

CDt1 and MCM (minichromosome maintenance associate)

Question 8

LF step 4

Answer 8

CDC6 gone in S phase

MCM still there

Question 9

LF step 5

Answer 9

G2, only ORC and ARS remains

Question 10

What are displaced by replication

Answer 10

CDC6, MCM2,3,5 and CDT1

Question 11

What prevents reinitation of replication?

Answer 11

degradataion of CDC6

Question 12

Post replication complex:

Answer 12

ORC bound to the origin

Question 13

What MCM’s can only enter after mitosis is completed?

Answer 13

MCM 2, 3 and 5

Question 14

The players in eukaryotic replication step 1

Answer 14

RPA binds

Question 15

euk rep step 2

Answer 15

pol alpha/primase binds

Question 16

euk rep step 3

Answer 16

RFC displaces pol alpha/primase

Question 17

euk rep step 4

Answer 17

PCNA binds RFC

RFC/PCNA/ pol delt complex extends nascnet DNA and keeps going

Question 18

euk rep step 5

Answer 18

RnaseH and MF1 remove the RNA primer

Question 19

euk rep step 6

Answer 19

The gap is filled

Question 20

euk rep step 7

Answer 20

the fragments are joined by ligase

Question 21

Player 5

Answer 21

RFC/PCNA/Pol delta complex

Question 22

Player 6

Answer 22

MF1 to extend the 5’-3’ exonuclease

Question 23

Player 7

Answer 23

RNaseH removes the RNA primer

Question 24

Player 8

Answer 24

DNA ligase seals the strands

Question 25

Player 9

Answer 25

DNA helicase opens the double helix (MCMs)

Question 26

When are active genes usually transcribed?

Answer 26

Early in S phase

Question 27

When are late genes usually transcribed?

Answer 27

Late in S phase

Question 28

Does early replication keep a gene active?

Answer 28

Obtaining the limiting transcription factors can help it stay active

Question 29

Does an active gene promote early replication?

Answer 29

open chromatin conformation near an active gene allows the formation of replication complexes More often it's this reason

Question 30

When is CDC6 synthesized?

Answer 30

only during G1