Dna Structure And Function

Front 1

purines

Back 1

1. A and G

2. two rings

Front 2

pyrimidines

Back 2

1. C and T

2. one rings

Front 3

separating DNA strands

Back 3

1. DNA gyrase

2. helicase

3. SSB

Front 4

DNA gyrase

Back 4

* class II topoisomerase
* responsible for uncoiling the DNA ahead of the replication fork

Front 5

helicase

Back 5

* responsible for uncoiling the DNA at the replication fork

Front 6

SSB

Back 6

* single stranded binding protein
* responsible for keeping DNA unwound after helicase
* stabilize ss DNA (by binding to it)

Front 7

DNA synthesis directionality

Back 7

synthesized 5' --> 3'

Front 8

DNA synthesis requirements

Back 8

1. primase

2. DNA polymerase

3. DNA synthesis

Front 9

DNA primase

Back 9

makes complementary RNA primer

Front 10

DNA Poly I (prokarytoic)

Back 10

1. DNA repair/proofreading

2. adds nucleotides b/w Okazaki frags

Front 11

DNA Poly II (prokarytoic)

Back 11

primase

Front 12

DNA Poly III (prokarytoic)

Back 12

main polymerase involved in replication

Front 13

DNA Poly IV (prokarytoic)

Back 13

1. error prone

2. mutagenic repair polymerase (SOS)

Front 14

DNA Poly V (prokarytoic)

Back 14

1. involved in SOS response and translesion synthesis

2. mutagenic repair

Front 15

when does replicaiton occur? how many times?

Back 15

1. occurs during S phase

2. occurs only once (even during two divisions)

Front 16

what would happen if DNA replication where completely conservative? (Meselson-Stahl expt)

Back 16

only heavy and light DNA would be seen

Front 17

what would happen if DNA replication where completely dispersive? (Meselson-Stahl expt)

Back 17

everything would be of intermediate weight

Front 18

what would happen if DNA replication was semiconservative? (Meselson-Stahl expt)

Back 18

1. first round: intermediate DNA

2. second round: one heavy, one intermediate band

DNA replication is semi-conservative

Front 19

3' → 5' exonuclease activity

Back 19

DNA poly proof-reading activity

Front 20

mismatch repair

Back 20

cuts unmethylated DNA strand (new strand) and repairs mismatch

Front 21

base excision repair

Back 21

damaged base is cut out along with surrounding bases

Front 22

nucleotide-excision repair

Back 22

1. damaged nucleotide(s) gets cut out and then polymerase replaces it

2. not mismatch repair

3. ex: thymine dimers

Front 23

nick translation:

Back 23

1. 5' → 3' exonuclease activity coupled to polymerase

2. bad nucleotides replaced with new ones

3. ex: RNA primers replaced by DNA

Front 24

SOS response in E.coli

Back 24

1. too much DNA damage

2. poly replicates over damaged DNA

3. high error rates better than no replication

Front 25

restriction enzymes

Back 25

1. sticky ends (hybridizable)

2. blunt ends (non-hybridizable)

3. open up plasmid for gene insertion

Front 26

plasmid requirements for cloning

Back 26

1. origin of replication

2. restriction site

3. antibiotic resistance

Front 27

PCR

Back 27

1. denaturation (separation), annealing (primers to template), elongation

2. amplification of original DNA is 2^#cycles