17 dna replication 1

Question 1

the enzyme that causes the 5’->3’ addition of the correct base

Answer 1

DNA polymerase III (prokaryotic)

Question 2

what fuels dNTP addition?

Answer 2

2 phosphate groups

Question 3

DNA polymerase 1 has what kind of activity?

Answer 3

5’ exonuclease

Question 4

these things cut DNA into large pieces within the strand

Answer 4

endonucleases

Question 5

DNA polymerase III and dna polymerase I have what kind of activity?

Answer 5

3’ exonuclease

Question 6

the three functions of DNA polymerase III?

Answer 6

1. tests that the base is correct. 2. synthesizes a phosphodiester bond. 3. proofreading with 3’ exonuclease

Question 7

explain the polymerase activity of dna pol III

Answer 7

5’->3’, processive with beta clamp, fast, needs RNA primer to start

Question 8

explain the 3’ exonuclease activity of DNA pol III

Answer 8

cuts nucleotides at 3’ end, super-vigilant proofreader. LOW mutation rate

Question 9

gyrase is also known as what?

Answer 9

topoisomerase II

Question 10

helicase does what?

Answer 10

breaks H bonds

Question 11

primase does what?

Answer 11

makes primers

Question 12

what is the sliding clamp composed of and how wide is it?

Answer 12

two beta subunits, 35angstroms

Question 13

two fun facts about replication:

Answer 13

it is semiconservative and bidirectional

Question 14

okazaki fragments require what before they are synthesized?

Answer 14

RNA primer

Question 15

which direction does the leading strand grow in?

Answer 15

TOWARDS the replication fork

Question 16

which direction does the lagging strand grow in?

Answer 16

AWAY from the replication fork

Question 17

the primosome is composed of what?

Answer 17

helicase and primase

Question 18

what enzyme stabilises the single strands?

Answer 18

single stranded binding proteins

Question 19

this enzyme removes the RNA primer and fills the gaps

Answer 19

DNA polymerase I

Question 20

this enzyme joins the individual okazaki fragments together with a phosphodiester bond

Answer 20

DNA ligase

Question 21

what enzyme is the primase and what does it do?

Answer 21

RNA polymerase. it can synthesize de novo strands. NO 3’ exonuclease function, removed and replaces w/dna. RIBOSE, easy to identify

Question 22

function of DNA pol 1 in the cell

Answer 22

primer filling, DNA repair

Question 23

function of DNA pol III in the cell

Answer 23

DNA replication

Question 24

nucleotides/sec for Pol I

Answer 24

20

Question 25

nucleotides/sec for Pol III

Answer 25

250-1000

Question 26

does Pol I have 5’ exonuclease activity?

Answer 26

yes

Question 27

does DNA pol III have 5’ exonuclease activity?

Answer 27

NO

Question 28

which one is a monomer, which one is a multimer?

Answer 28

Pol 1 is a monomer, pol III is a multimer