DNA replication and repair -- Lecture 6

Question 1

direction of DNA replication:

Answer 1

5’ –> 3’

Question 2

DNA Pol III needs a ___ to attach a new nucleotide to

Answer 2

3’-OH

Question 3

___ needs a 3’-OH to attach a new nucleotide to a new strand of DNA

Answer 3

DNA Pol III

Question 4

is DNA Pol III able to add the first nucleotide in DNA replication?

Answer 4

NO

Question 5

what begins the DNA replication?

Answer 5

primase

Question 6

primase (what is it and what it does)

Answer 6

doesn’t have limitation that DNA Pol III has

a type of RNA polymerase

begins the DNA replication process

Question 7

DNA replication:

new RNA nucleotides are added to leading strand ___ by primase

Answer 7

faster

Question 8

DNA replication:

new RNA nucleotides are added to lagging strand ___ by primase

Answer 8

slower

Question 9

how to remove the RNA?

Answer 9

DNA polymerase I removes and replaces the RNA nucleotides w/ DNA nucleotides

Question 10

removal of RNA:

___ removes and replaces RNA nucleotides w/ DNA nucleotides

Answer 10

DNA polymerase I

Question 11

DNA polymerase I ___ the RNA nucleotides w/ DNA nucleotides

Answer 11

removes and replaces

Question 12

DNA Polymerase I removes and replaces the ___ w/ ___

Answer 12

RNA nucleotides w/ DNA nucleotides

Question 13

RNA removal and nick repair:

“nicks”

Answer 13

missing phosphodiester bonds

Question 14

RNA removal and nick repair:

missing phosphodiester bonds

Answer 14

nicks

Question 15

RNA removal and nick repair:

DNA Pol I (does what)

Answer 15

1) removes the RNA nucleotides
2) replaces them w/ DNA nucleotides
3) can’t form the last phosphodiester bond, leaving a ‘nick’ in the DNA backbone

Question 16

RNA removal and nick repair:

DNA Ligase (does what)

Answer 16

1) enzyme that restores the missing phosphodiester bonds that DNA Pol I leaves behind –> “nick repair”

Question 17

RNA removal and nick repair:

Okazaki fragments

Answer 17

fragments of the duplications in the lagging strand that are being converted from RNA to DNA

Question 18

DNA polymerase processivity:

DNA polymerases are enzymes w/ high ___

Answer 18

processivity

Question 19

DNA polymerase processivity:

___ are enzymes w/ high processivity

Answer 19

DNA polymerases

Question 20

DNA polymerase processivity:

DNA polymerases are ___ w/ high processivity

Answer 20

enzymes

Question 21

DNA polymerase processivity:

DNA polymerases can add ___ w/o falling off of the DNA (very stable)

Answer 21

thousands of nucleotides

Question 22

DNA polymerase processivity:

DNA polymerases can add thousands of nucleotides w/o ___ (very stable)

Answer 22

falling off of the DNA

Question 23

DNA polymerase processivity:

DNA polymerases can add thousands of nucleotides w/o falling off of the DNA (___)

Answer 23

very stable

Question 24

DNA polymerase processivity:

___ can add thousands of nucleotides w/o falling off of the DNA (very stable)

Answer 24

DNA polymerases

Question 25

DNA polymerase processivity:

why are DNA polymerases so stable?

Answer 25

a protein called “sliding clamp protein” stabilizes the interaction b/n DNA polymerases and the DNA

Question 26

DNA polymerase processivity:

“sliding clamp protein” (what does it do)

Answer 26

stabilizes the interaction b/n DNA polymerase and the DNA

Question 27

what happens when there is a mistake in DNA replication?

Answer 27

if DNA polymerase adds an incorrect nucleotide, it can replace it w/ the correct nucleotide

Question 28

what happens when there is a mistake in DNA replication?

if DNA polymerase adds an ___, it can replace it w/ the ___

Answer 28

incorrect nucleotide

correct nucleotide

Question 29

what happens when there is a mistake in DNA replication?

if ___ adds an incorrect nucleotide, it can replace it w/ the correct nucleotide

Answer 29

DNA polymerase

Question 30

what happens when there is a mistake in DNA replication?

DNA polymerase has a ___ function

Answer 30

proofreading function

Question 31

what happens when there is a mistake in DNA replication?

___ has a proofreading function

Answer 31

DNA polymerase

Question 32

DNA repair enzymes:

DNA repair enzymes ___ DNA damage

Answer 32

find and repair

Question 33

DNA repair enzymes:

___ find and replace DNA damage

Answer 33

DNA repair enzymes

Question 34

DNA repair enzymes:

DNA repair enzymes find and replace ___

Answer 34

DNA damage

Question 35

DNA repair enzymes:

excision repair enzymes ___ mismatches and DNA damage (e.g. thymidine dimers)

Answer 35

detect and repair

Question 36

DNA repair enzymes:

excision repair enzymes detect and repair ___ (e.g. thymidine dimers)

Answer 36

mismatches and DNA damage

Question 37

DNA repair enzymes:

___ detect and repair DNA damage (e.g. thymidine dimers)

Answer 37

excision repair enzymes

Question 38

DNA repair enzymes:

our DNA repairing enzymes are constantly at work repairing our DNA (true/false)

Answer 38

true

Question 39

deficiencies in DNA repair enzymes:

xeroderma pigmentosum (XP) – what is it

Answer 39

rare genetic disorder of DNA repair enzymes

Question 40

deficiencies in DNA repair enzymes:

in XP patients, excision repair enzymes have a significantly reduced ability to ___

Answer 40

repair DNA damage

Question 41

deficiencies in DNA repair enzymes:

in XP patients, excision repair enzymes have a ___ ability to repair DNA damage

Answer 41

significantly reduced

Question 42

deficiences in DNA repair enzymes:

Xeroderma pigmentosum leads to…

___% of patients die before 20

Answer 42

development of cancers frequently and at a young age

60%

Question 43

deficiencies in DNA repair enzymes:

ER enzymes are ___

Answer 43

critical for survival

Question 44

deficiencies in DNA repair enzymes:

___ are critical for survival

Answer 44

ER enzymes