6.3 and 6.4

Question 1

Average human chromosome nucleotide

Answer 1

250 million

Question 2

Transcription factors

Answer 2

turn genes on or off

Question 3

Restriction enzymes

Answer 3

cut DNA at particular sites

Question 4

Sequence-specific DNA-binding proteins

Answer 4

Restriction enzymes or transcription factors

Question 5

Catabolite gene activator protein (CAP)

Answer 5

recognize specific base-pair sequences in major groove of double helix

Question 6

Proteins can access genetic info of DNA

Answer 6

without dissembling the double helix

Question 7

Unwinding of DNA

Answer 7

exposes a single sequence of bases on each of two strands

Question 8

Prokaryotes DNA

Answer 8

double stranded, closed circular chromosome

Question 9

Eukaryotes DNA

Answer 9

double-stranded linear chromosomes

Question 10

Virus DNA

Answer 10

single or double stranded, circular, or linear

Question 11

Retroviruses (Polio and AIDS) genetic material

Answer 11

use ribonucleic acid (RNA)

Question 12

RNA sugar

Answer 12

ribose

Question 13

RNA length

Answer 13

fewer nucleotides than DNA

Question 14

RNA strands

Answer 14

flexible and some regions can fold back and form base pairs with other parts of molecule

Question 15

RNA is ____ stable than DNA

Answer 15

less

Question 16

Complementary base pairing ensures

Answer 16

semi-conservative replication

Question 17

SEmiconservative replication

Answer 17

copying in which one strand of each new double helix is conserved from the parent molecule and the other is completely new

Question 18

Conservative replication

Answer 18

one helix is completely conserved while the other helix is made of two new strands

Question 19

Dispersive replication

Answer 19

both daughter helix’s would contain new and parent material

Question 20

Matthew Meselson and Franklin Stahl

Answer 20

In 1958, confirmed the semiconservative nature of DNA

Question 21

Control in Meselson and Stahl experiment

Answer 21

All nitrogen was in normal isotope N14

Question 22

During S-phase of interphase

Answer 22

cell replicates the double helix semiconservatibely

Question 23

DNA polymerase

Answer 23

enzyme that forms a new DNA strand during replication by adding nucleotides reverse complementary to a template

Question 24

Arthur Kornberg

Answer 24

purified components of the replication mechanism
1. DNA template
2. Primer
3. Nucleotide triphosphates

Question 25

dNTP

Answer 25

high energy phosphate bonds that is need to synthesize every DNA molecule

Question 26

Primer

Answer 26

short, preexisiting DNA oligonucleotide or RNA molecule to which nucleotides can be added by DNA polymerase

Question 27

DNA polymerase cannot

Answer 27

establish the first link in a new chain (need to start with primer)

Question 28

Stages of replication

Answer 28

Initiation and elogation

Question 29

Initiation

Answer 29

proteins open up the double helix and prepare it for complementary base pairing

Question 30

elongation

Answer 30

proteins connect the correct sequence of nucleotides on both newly formed DNA helix

Question 31

Origin of replication

Answer 31

short sequence of nucleotides where DNA replication initiates

Question 32

Initiator protein binds to origin and attracts

Answer 32

DNA helicase

Question 33

DNA helicase

Answer 33

enzyme that unwinds the double helix

Question 34

DNA polymerase III

Answer 34

adds nucleotides to the 3' end of a preexisting strand of nucleic acid

Question 35

Living cells need ____ for replication

Answer 35

RNA primers

Question 36

Primase

Answer 36

synthesize RNA primer

Question 37

DNA polymerase III catalyzes

Answer 37

polymerization

Question 38

polymerization

Answer 38

joining of a new nucleotide to the preceding nucleotide through the formation of a phosphodiester bond

Question 39

DNA polymerase molecule moves along

Answer 39

anti-parallel template (3'-to-5' direction)

Question 40

DNA construction moves in

Answer 40

5'-to-3' direction

Question 41

Leading strand

Answer 41

DNA strand replicated continuously 5' to 3' toward the unwinding Y-shaped replication fork

Question 42

Lagging strand

Answer 42

discontinuously replicated t-to3 direction

Question 43

Okazaki fragments

Answer 43

small fragment (about 1000 bases) joined after synthesis to form lagging strand

Question 44

DNA polymerase I

Answer 44

replace the RNA primer of the previously made Okazaki fragment with DNA

Question 45

DNA ligase

Answer 45

joins Okazaki fragments into a continuous strand of DNA

Question 46

Replication is

Answer 46

bidirectional

Question 47

Supercoiling

Answer 47

Additional twisting of the DNA molecule caused by movement of the replication fork during unwinding

Question 48

Toposimoerase

Answer 48

relaxes supercoils by breaking, unwinding and suturing the DNA by separate (nicking) daughter chromosomes

Question 49

Telomeres

Answer 49

Specialized terminal structures on eukaryotic chromosomes that ensure maintenance and accurate replication of the two ends of each linear chromosome