Unit 11

Question 1

Untwists the double helix at the replication fork & separates the 2 parent strands into templates

Answer 1

Helicase

Question 2

Corrects “overwinding” ahead of replication fork by breaking, swiveling, & rejoining DNA strands

Answer 2

Topoisomerase

Question 3

Puts the fragments together on the lagging strand (link, glue)

Answer 3

DNA Ligase

Question 4

Enzyme that looks for mistakes, cuts them out, and repairs them before they mutate

Answer 4

Nuclease

Question 5

Messenger

Answer 5

RNA primer

Question 6

Enzyme that helps the initial nucleotide primer strand of RNA

Answer 6

RNA primase

Question 7

Starts RNA chain from scratch / we need it b/c DNA can’t start its process

Answer 7

RNA primase

Question 8

Binds to & stabilizes single stranded DNA until it can be used as a template

Answer 8

Single strand binding protein

Question 9

Where is this the double helix credited from?

Answer 9

Watson & Crick

Question 10

What are the back bone ladders of the double helix made of?

Answer 10

repeating phosphate sugars

Question 11

What are the 4 nitrogen bases?

Answer 11

Adenine, Guanine, Thymine, Cytosine

Question 12

What is equivalent to one unit?

Answer 12

1 phosphate group, 1 nitrogen base, 1 sugar

Question 13

Between nitrogen bases, how is DNA held together?

Answer 13

Hydrogen bonds

Question 14

What are hydrogen bonds the most practical bonds for this?

Answer 14

Stable enough to hold together DNA, weak enough to split apart, replicate, then come back together

Question 15

how many bonds to G & C have?

Answer 15

3

Question 16

How many bonds do A & T have?

Answer 16

2

Question 17

What type of bond holds together the back bone?

Answer 17

Covalent (strong)

Question 18

How many molecules are purines?

Answer 18

2

Question 19

How many molecules are pyrimidines?

Answer 19

1

Question 20

Which nitrogen bases are purines?

Answer 20

A & G

Question 21

Which nitrogen bases are pyrimidines?

Answer 21

T & C

Question 22

How many daughter strands are made from the parent during DNA replication, and why is that?

Answer 22

2 daughter strands, and the base pairing rule

Question 23

Enzyme that adds new nucleotides

Answer 23

Polymerase

Question 24

Catalyzes the elongation of new DNA at replication

Answer 24

Polymerase

Question 25

Requires primer + DNA template strand

Answer 25

Ploymerase

Question 26

Adds nucleotides to the 3 prime end of the new strands

Answer 26

Polymerase

Question 27

Analyzed the chemical compound of nitrogen bases

Answer 27

Chargaff

Question 28

What is the purpose of DNA replication?

Answer 28

To ensure continuity of heredity

Question 29

DNA molecule containing one original strand & a newly synthesized strand

Answer 29

Semi-conservative

Question 30

Phosphate terminus

Answer 30

5' end

Question 31

Hydroxyl terminus

Answer 31

3' end

Question 32

How do the two strands run?

Answer 32

Anti-parallel

Question 33

The one strand that is always made continuously

Answer 33

Leading strand

Question 34

The one strand that is made discontinuously

Answer 34

Lagging strand

Question 35

Location where 2 strands are separated

Answer 35

Replication fork

Question 36

What phase does DNA replication occur in?

Answer 36

S phase

Question 37

When the original double helix does not change at all, and it it an exact replica

Answer 37

Conservative

Question 38

Every daughter strand contains some parental DNA, but it is dispersed in bubbles of DNA

Answer 38

Dispersive

Question 39

The signal where replication should originate

Answer 39

Primer site

Question 40

The lagging strand consists of tiny pieces called...

Answer 40

Okazaki fragments

Question 41

What proofreads the newly added bases?

Answer 41

DNA polymerase

Question 42

What are the two types of repairs polymerase does?

Answer 42

Mismatch & excision

Question 43

Influences replication process

Answer 43

Directionality