Dna Replication

Question 1

3000 nucleotides/min (human) 45000 nucleotides/min e. coli

Answer 1

speed of DNA replication

Question 2

very precise, 1 error/100 million nucleotides

Answer 2

accuracy of DNA replication

Question 3

initiation, elongation, termination

Answer 3

3 phases in DNA replication

Question 4

replication origin is recognized by initiator enzymes that bind to it, creating a replication bubble that will extend at each end at the replication fork

Answer 4

initiation

Question 5

specific nucleotide sequence of 100-200 base pairs

Answer 5

replication origin

Question 6

unwinds short DNA segments, breaks hydrogen bonds

Answer 6

DNA helicase

Question 7

hold the strands apart by blocking hydrogen bonding on base pairs

Answer 7

single stranded binding proteins

Question 8

relieves tension that results from the unwinding of the DNA strand making DNA flat

Answer 8

DNA gyrase

Question 9

adds a rna primer at the location where DNA polymerase III will begin replication

Answer 9

RNA primase

Question 10

enters replication bubble and adds nucleotides to parental strands building from 5’ to 3’, proofreading as it goes

Answer 10

DNA polymerase III

Question 11

removes rna primers from daughter strand proofreading as it goes

Answer 11

DNA polymerase I

Question 12

seals the okazaki fragments together through forming phosphodiester bonds

Answer 12

DNA ligase

Question 13

5’ to 3’ direction, same direction as replication fork by DNA polymerase 3 attached to RNA primer

Answer 13

leading strand

Question 14

discontinuously synthesized

Answer 14

lagging strand

Question 15

will always be at 5’ end of each daughter molecule where primer was placed unpaired nucleotides because of opposite direction, with each replication more DNA is lost

Answer 15

termination

Question 16

stretches of highly repetitive sequences containing a lot of G nucleotides, loss of repetitive sequences prevents against important cell info lost

Answer 16

telomeres

Question 17

DNA polymerase I and III, hydrogen bonding and nucleotide pairing is checked, exonuclease removing and replacing

Answer 17

proofreading

Question 18

dna polymerase II checks for shape of DNA (base pairing) and then removes, DNA ligase seals back the sugar phosphate backbone

Answer 18

correction