Final (ch 20)

Question 1

The 3’-5’ exonuclease activity of E.coli DNA polymerase III accounts for this of polymerization

Answer 1

low error rate

Question 2

An okazaki fragment is

Answer 2

small segment of DNA that is an intermediate in the synthesis of the lagging strand

Question 3

what effect does topoisomerases have upon DNA

Answer 3

changes the supercoiling of DNA

Question 4

Replication of eukaryotic DNA must be this

Answer 4

controlled to coordinate with the cell cycle

Question 5

single strand binding proteins are important for preventing this

Answer 5

single stranded DNA from rewinding and protecting it from degradation

Question 6

in most organisms replication proceeds in this mannor from here

Answer 6

bidirectional

replication origin

Question 7

An E.coli has this many replication forks on ints ingle chromosome: humans have this many replication forks on each chromosome

Answer 7

2

many

Question 8

These attack ssDNA

Answer 8

nucleases

Question 9

3 features of NDA replication

Answer 9

semiconservative
bidirectional
semi-discontinuous

Question 10

what does semi discontinuous mean

Answer 10

leading strand copies continuously

lagging strand copies in segments which must be joined

Question 11

DNA molecules are supercoiled in this mannor in vivo

Answer 11

negatively

Question 12

why are they negatively supercoiled

Answer 12

helps replication machinery gain access to the two template strands

Question 13

which phase is DNA replicated in

Answer 13

S

Question 14

Which phase has rapid grown and metabolic activity

Answer 14

G1

Question 15

which phase has grown and preparation for cell division

Answer 15

G2

Question 16

How long to replicate DNA in eukaryotes

Answer 16

8 hours

Question 17

This alters DNA supercoiling

Answer 17

topoisomerases

Question 18

this is the site where DNA strands separate and new strands are synthesized

Answer 18

replication fork

Question 19

Bacterial DNA replication is done in this mannor

Answer 19

bidirectional

Question 20

this is the machinery for replication in bacterial DNA

Answer 20

replisome

Question 21

how long to duplicate E.coli dna

Answer 21

38 min

Question 22

convert dsDNA to ssDNA

Answer 22

helicase

Question 23

binds ssDNA

Answer 23

single-stranded binding protein

Question 24

makes RNA primers

Answer 24

primase

Question 25

extends the new chain through polymerization of dNTP's

Answer 25

DNA polymerase

Question 26

removes the RNA primer

Answer 26

Rnase

Question 27

joins the two DNA (Okazaki) fragments

Answer 27

DNA ligase

Question 28

anti parallel strands of dna are replicated simultaneously

Answer 28

T

Question 29

DNA can only extend a prexisting chain

Answer 29

T

Question 30

RNA primers are this long

Answer 30

10-60 nucleoties long

Question 31

involved in repairing and patching DNA, single polypeptied chain

Answer 31

DNA polymerase I

Question 32

strictly a repair enzyme, multi subunits

Answer 32

DNA polymerase II

Question 33

major DNA replication enzyme, responsable for chain elongation

Answer 33

DNA polymerase III

Question 34

This strand is formed semidiscontinuously

Answer 34

lagging strand

Question 35

This is the leading most compound in DNA synth

Answer 35

DNA gyrase

Question 36

How often does DNA polymerase make an error

Answer 36

only once in ever 10^9 ro 10^10

Question 37

This compound does both proofreading and repair functions

Answer 37

DNA polymerase I

Question 38

Cut and patch process

Answer 38

nick translation

Question 39

Discontinuous segments of the lagging strand are joined by this, requiring hydrolysis of high energy bonds

Answer 39

ligase

Question 40

This repeatedly adds nucleotides to the 3' end of DNA called this

Answer 40

telomerase | telomeres

Question 41

an alteration in a cell's DNA is call a

Answer 41

mutation

Question 42

cells with badly damaged DNA are susceptible to this

Answer 42

apoptosis

Question 43

cells with damaged DNA that excape normal growth-control and proliferate excessively often result in this

Answer 43

cancer

Question 44

only macromolecule that can be repaired

Answer 44

DNA

Question 45

Lesions may be fixed by this which does not require breaking the phosphodiester backbone of DNA

Answer 45

direct repair

Question 46

These are common culprits for DNA damage

Answer 46

reactive oxygen species

Question 47

nucleotide substitution is this

Answer 47

point mutation

Question 48

changing a purine to a different purine or pyrimidine to a different pyrimidine

Answer 48

transition mutation

Question 49

chaning a purine to a pyriumidine or vice versa

Answer 49

transverse mutation

Question 50

DNA base is removed

Answer 50

Abasic mutation

Question 51

These can also alter base identity

Answer 51

deamination

Question 52

This can remove meythl groups from DNA bases

Answer 52

methyltranferase

Question 53

a damaged base is excised from sugar-phosphate back bone by this (most common DNA lesion)

Answer 53

DNA glycosylase

Question 54

Recombination can do this

Answer 54

restore broken DNA molecules by splicing two peices of DNA together