dna replication 5

Question 1

what are the 4 molecules both prokaryotes and eukaryotes use

Answer 1

helicases
ssbs
rna primers
dna polymerases

Question 2

where does eukaryotic dna replication occur

Answer 2

in the nucleus

Question 3

what’s the 4 differences between prokaryotic and eukaryotic replication

Answer 3

more genetic material
more than one chromosome
linear chromosomes
additional packaging

Question 4

how many points of origin do eukaryotes have per chromosome

Answer 4

10-1000s

Question 5

are prokaryotic or eukaryotic polymerases slower and what is eukaryotic polymerases speed

Answer 5

eukaryotic
1000 nt/ sec

Question 6

what do eukaryotic dna polymerasesnot contain

Answer 6

5’-3’ exonuclease

Question 7

which have longer Okazaki fragments; eukaryotic or prokaryotic

Answer 7

prokaryotic

Question 8

what is the origin of replication called in eukaryotes and what is the region rich in

Answer 8

autonomously replication sequences
rich in AT

Question 9

in what phase of the cell cycle does initiation occur in

Answer 9

the G1 phase

Question 10

what initiates the whole process of replication

Answer 10

binding of OCR to the dna

Question 11

during the G1 phase what accumulate in the nucleus and what specific proteins will bind to the OCR

Answer 11

licensing factors
cdc-1 and cdt-1 will bind to the OCR

Question 12

what is the function of cdc-1

Answer 12

loading helicase onto the dna

Question 13

what phase doe activation happen in

Answer 13

s phase

Question 14

what is added to helicase to activate it and what is this complex called

Answer 14

additional proteins and dna polymerases
- the complex is called the replisome progression complex

Question 15

what is passive replication

Answer 15

when one replication fork passes through a region with a point of origin in it, without activating it

Question 16

what are 3 features of polymerase a

Answer 16

• it is self-priming
• it cannot proofread
• it does not associate with PCNA

Question 17

what loads pcna onto the dna

Answer 17

replication factor c

Question 18

what does polymerase b do

Answer 18

repair

Question 19

what does polymerase y do

Answer 19

replication of mtDNA

Question 20

what does polymerase o do

Answer 20

works on the lagging stand

Question 21

what does polymerase e do

Answer 21

works on the leading strand

Question 22

how do polymerase o and e deal with rna primers

Answer 22

they create an rna flap, where the DNA is hanging off and rnase h1 will digest it but will leave one nt of rna

Question 23

what removes the final nt of rna/ any incorrect dna

Answer 23

flap 1 endonuclease

Question 24

where are telomeres located and why are they important for the chromosome

Answer 24

at the end of the chromosome
they are important as where rna primers are placed and removed, gene shrinkage can occur
telomeres act as a non important region so it wont matter if it is lost

Question 25

what is the hayflick limit

Answer 25

where all the telomeric dna has been used, and important genes will begin to be lost

Question 26

how can we overcome the hayflick limit and what protein is used for this

Answer 26

synthesise more telomeric dna telomerase

Question 27

how does telomerase work and what type of protein is it

Answer 27

it works by acting as a template, so pol a will continue to extend it ribonucleoprotein

Question 28

what is the lagging strand in mtdna made of

Answer 28

rna okazaki fragments

Question 29

what is 2 features of mtdna replication

Answer 29

-circular -unidirectional

Question 30

what mechanism do bacteriophages use for replication

Answer 30

rolling circle mechanism

Question 31

what do rna genomes use to replicate and what are 2 features about it

Answer 31

rna replicase -self priming, no proof reading

Question 32

how do retroviruses create dna strands and what enzyme do they use

Answer 32

they create a dna strand from rna template, then degrade the rna half, and create the other DNA strand from the first DNA strand (hard to make sound right soz) they kinda just make a dna-rna hybrid and then get rid of the rna side and make just a full DNA reverse transcriptase