Day 1 Test 2

Question 1

Enzyme that synthesizes DNA

Answer 1

DNA Polymerase

Question 2

DNA Polymerase adds nucleotides at __ end of a growing DNA strand using old strand___.

Answer 2

Adds nucleotides at 3’ end of a growing DNA strand using old strand as a template

Question 3

DNA Polymerase catalyzes formation of ____ bonds between ____ of last nucleotide in strand with ____ of incoming nucleotide

Answer 3

DNA Polymerase catalyzes formation of phosphodiester bonds between 3’ OH group of last nucleotide in strand with 5’ phosphate of incoming nucleotide

Question 4

DNA Polymerase can only add nucleotides to a g____ DNA strand.

Answer 4

DNA Polymerase can only add nucleotides to a growing DNA strand (cant start a new strand from scratch)

Question 5

DNA Polymerase after adding a nucleotide, DNA polymerase _____

Answer 5

DNA Polymerase after adding a nucleotide, DNA polymerase stays attached to chain

Question 6

(T/F) The replication fork is symmetrical

Answer 6

False. The replication fork is asymmetrical

Question 7

DNA is only synthesized in ____direction

Answer 7

DNA is only synthesized in 5’ to 3’ direction

Question 8

At the replication fork one strand is growing overall at its ____.

Answer 8

At the replication fork one strand is growing overall at its 3’ end

Question 9

In the leading strand DNA:

Answer 9

In the leading strand DNA is synthesized continuously from 5’ to 3’

Question 10

In the lagging strand:

Answer 10

DNA is synthesized discontinuously in separate, small pieces called okazaki fragments

Question 11

Okazaki fragments are synthesized ____ direction

Answer 11

Okazaki fragments are synthesized 5’ to 3’

Question 12

On lagging strand, DNA growing in ____ direction

Answer 12

On lagging strand, DNA growing in 3’ to 5’ direction

Question 13

On _____ strand, DNA growing in 3’ to 5’ direction

Answer 13

On lagging strand, DNA growing in 3’ to 5’ direction

Question 14

At lagging strand, DNA polymerase is moving _____ in relation to the fork

Answer 14

At lagging strand, DNA polymerase is moving backwards from the fork (backstitching)

Question 15

(T/F) DNA Polymerase is Self-Correcting

Answer 15

True

Question 16

DNA polymerase has a 3’ to 5’ _____ activity

Answer 16

DNA polymerase has a 3’ to 5’ exonuclease activity

Question 17

____ required to start synthesis of a DNA strand

Answer 17

Primase

Question 18

Primase begins new strand by…

Answer 18

Primase can begin a new strand by joining 2 nucleotides together

Question 19

Leading strand needs ___ primer(s)

Answer 19

Leading strand only needs one primer

Question 20

(T/F) Leading strand needs at least 2 primers

Answer 20

False. Leading strand only needs one primer

Question 21

Lagging strand needs ____ primer(s)

Answer 21

Lagging strand needs many primers – one for every okazaki fragment (about every 200 nucleotides)

Question 22

Lagging strand needs ___ primer(s)

Answer 22

Lagging strand needs many primers – one for every okazaki fragment (about every 200 nucleotides)

Question 23

Okazaki fragments are about ___ nucleotides long.

Answer 23

okazaki fragments are about 200 nucleotides long.

Question 24

If correct nucleotide is added by DNA polymerase…

Answer 24

DNA polymerase adds next nucleotide

Question 25

If incorrect nucleotide is added by DNA polymerase...

Answer 25

DNA polymerase removes incorrect nucleotide by cutting the bond then adds correct nucleotide

Question 26

DNA polymerase has a _____ direction exonuclease activity

Answer 26

DNA polymerase has a 3’ to 5’ exonuclease activity

Question 27

primase makes a short stretch of RNA about____ long is base-paired to template strand

Answer 27

10 nucleotides

Question 28

A short stretch of RNA is called a ____.

Answer 28

Primer, because it provides a 3’ end for DNA polymerase to use for DNA synthesis

Question 29

Primer is later removed by ____.

Answer 29

nucleases that recognize RNA in an RNA/DNA duplex and excise it

Question 30

Gap left by removal of primer is filled by _____

Answer 30

DNA repair polymerase

Question 31

DNA repair polymerase fills gap left by removal of primer with ______ as a primer.

Answer 31

DNA repair polymerase fills gap left by removal of primer with adjacent okazaki fragment as a primer.

Question 32

DNA repair polymerase fills gap left by removal of primer with adjacent okazaki fragment as a _____.

Answer 32

primer.

Question 33

___ joins together the completed fragments

Answer 33

DNA ligase

Question 34

DNA ligase – joins together the completed fragments by ...

Answer 34

Catalyzing the formation of phosphodiester bonds

Question 35

DNA ligase – joins together the completed fragments by catalyzing the formation of phosphodiester bonds. ___ of one DNA fragment and ____ of adjacent DNA fragment

Answer 35

3’ OH of one DNA fragment and 5’ phosphate of adjacent DNA fragment

Question 36

___ A large, multi-subunit complex present at the replication fork

Answer 36

Replication Machine

Question 37

Replication Machine Contains... _ _ _ _ _

Answer 37

primase, DNA polymerase, helicase, single-strand binding protein, sliding clamp

Question 38

(T/F) Replication Machine complex moves along DNA to allow DNA synthesis on both strands

Answer 38

True, complex moves along DNA to allow DNA synthesis on both strands in a coordinated manner

Question 39

In replication machine ___ moves along the DNA helix and opens it up (separate 2 strands)

Answer 39

Helicase

Question 40

Helicase uses the energy of___

Answer 40

ATP hydrolysis

Question 41

___ exposes the single-stranded DNA template

Answer 41

Helicase

Question 42

___ binds to the single strands and prevents reformation of base pairs between the two original template strands

Answer 42

Single-strand binding protein

Question 43

___ keeps DNA polymerase firmly attached to the DNA, forms a ring around the DNA

Answer 43

Sliding clamp

Question 44

On the lagging strand DNA polymerase is ___ each time an okazaki fragment is completed

Answer 44

temporarily released. DNA polymerase and sliding clamp are released and may then re-associate with DNA to synthesize the next okazaki fragment

Question 45

(T,F) Sliding Clamp forms a ring around the DNA

Answer 45

True

Question 46

___ Special sequences at ends of chromosomes

Answer 46

telomeres are a repeated sequences that allow the ends to be replicated

Question 47

__ enzyme that binds to telomeres

Answer 47

Telomerase

Question 48

In humans the telomeres is

Answer 48

GGGTTA