DNA Replication

Question 1

Bidirectional Replication

Answer 1

replication begins in middle of DNA and proceeds in both directions

Question 2

Semiconservative

Answer 2

each copy of DNA contains one old and one new strand

Question 3

Single stranded binding proteins

Answer 3

bind to single strands to prevent reannealing and protect DNA from nuclease degeneration

Question 4

DNA Helicase

Answer 4

Splits 2 DNA strands apart

Question 5

Topoisomerase I

Answer 5

alleviates supercoiling

Cleaves one strand of DNA then religates the strand

Question 6

Topoisomerase II

Answer 6

alleviates supercoiling

cuts both strands to relieve supercoil, then religates them

Question 7

Lagging Strand

Answer 7

synthesized discontinuously

broken into Okazaki fragments that are later put back together

Question 8

Primase

Answer 8

RNA polymerase- copies first ~10 nucleotides to prime DNA synthesis at 3’ end

Question 9

DNA Polymerase

Answer 9

catalyzes reaction b/t 3’ OH group of strand being synthesized and 5’ triphosphate of incoming nucleotide

Question 10

DNA Polymerase III

Pol III

Answer 10

enzyme in prokaryotes that elongates leading and lagging strand
checks to make sure the right nucleotide was added

Question 11

DNA Polymerase I

Pol I

Answer 11

Removes RNA primer (5’-3’)
replaces rNTPs with dNTPs (5’-3’)
proofreads and corrects wrong nucleotides (3’-5’)

Question 12

DNA Ligase

Answer 12

seals nicks that remain after RNA primer is removed and replaced with dNTP

Question 13

G1 Phase

Answer 13

growth and metabolism

first gap

Question 14

G0 Phase

Answer 14

semipermanent

Question 15

G1 Phase

Answer 15

reentry into cell cycle

Question 16

S Phase

Answer 16

replication of DNA

Question 17

G2 Phase

Answer 17

second gap

prepares to divide

Question 18

M Phase

Answer 18

cell division

Question 19

Pol a (alpha)

Answer 19

contains primase + DNA polymerase

begins strand synthesis

Question 20

Pol d (delta)

Answer 20

DNA polymerase + proofreading (extends strands)

Question 21

Pol B and Pol e

beta and epsilon

Answer 21

DNA repair enzymes

Question 22

Pol y (gamma)

Answer 22

mtDNA polymerase

Question 23

Telomerase

Answer 23

extends ends of linear chromosomes

contains segment of RNA that is complimentary to telomere

Question 24

Reverse transcriptase

Answer 24

telomerase copies its own template (RNA) into DNA

Question 25

Strand directed mismatch repair

Answer 25

corrects errors made during replication