Replication - 16.2

Question 1

Replication of chromosomal DNA begins at

Answer 1

origins of replication

Question 2

Origin of replication

Answer 2

Short stretch of DNA

Question 3

Replication fork

Answer 3

Y-Shaped region where strands are unwound

Question 4

Helicases

Answer 4

Enzymes that untwist the dbl helix at the replication forks, separating the 2 parental strands, which become template strands

Question 5

ssBindingProteins

Answer 5

Bin unpaired DNA strands, keeping them from re-pairing

Question 6

Topoisomerase

Answer 6

Relieves strain caused by helicase by breaking, swivelling, rejoining strands

Question 7

Enzymes that synthesize DNA cannot initiate _____

Answer 7

the synthesis of a polynucleotide

Question 8

Initial nucleotide chain produced during DNA synthesis is

Answer 8

Short stretch of RNA, not DNA

Primer (5-10 nucleotides long)

Question 9

Primer synthesized by

Answer 9

Enzyme primase

Question 10

New DNA will start from the ____end of the RNA primer

Answer 10

3’

Question 11

DNA polymerases

Answer 11

Catalyze the synthesis of new DNA by adding nucleotides the the 3’ end of a preexisting chain
Fills in missing nucleotides

Question 12

DNA replication is _____(conservation)

Answer 12

Semi conservative

Question 13

Adenine nucleotide to make DNA

Answer 13

dATP

Question 14

Why are the nucleotides for DNA syn chemically reactive?

Answer 14

Triphosphate tails have an unstable cluster of negative charge

Question 15

As DNA polymerase catalyzes each dehydration RXN _______ lost.

Answer 15

2 phosphate groups are lost as a molecule of pryophosphate

Question 16

DNA polymerase catalyzes the addition of a nucleoside triphosphate to….

Answer 16

the 3’ end!

Question 17

A new DNA strand can elongate only in the ____ direction

Answer 17

5’ to 3’

Question 18

After RNA primer is made, ______ starts the synthesize the leading strand

Answer 18

DNA pol III

Question 19

Leading strand is elongated

Answer 19

Continuously

Question 20

The _____ moves DNA pol III along template strand

Answer 20

Sliding clamp

Question 21

Lagging strand elongates in the direction

Answer 21

AWAY from the replication fork

Question 22

Lagging synthesized in ______

Answer 22

okazaki segments, discontinuously

Question 23

RNA pol 1

Answer 23

Replaces the RNA nucleotides of the adjacent primer with DNA nucleotides

Question 24

DNA Ligase

Answer 24

Joins the sugar phosphate backbones of the Okazaki fragments into a continuous DNA strand
Seals the free end of the new DNA to the old DNA, completing the strand

Question 25

Nuclease

Answer 25

DNA-cutting-enzyme

removes damaged sections

Question 26

Mismatch repair

Answer 26

Repairing mismatched nucleotides which evade proofreading by DNA polymerase
Enzymes remove and replace incorrectly paired nucleotides

Question 27

Telomeres

Answer 27

In EUKaryotes, no genes (noncoding), mulltiple repitions of one short nucleotide sequence “TTAGGG” x54852 as an “aglet”
Postpone erosion of genes near the ends of chromosomes

Question 28

Telomerase

Answer 28

catalyzes lengthening of telomeres