Test 2

Question 1

T/F: RNA polymerase requires a primer to initiate polynucleotide synthesis.

Answer 1

False

Question 2

ALL of the following changes would decrease the melting temperature of DNA EXCEPT:
a) Increasing the concentration of magnesium (Mg2+), a cation
b) Increasing the pH
c) Addition of non-polar solvents
d) Increasing the number of base pair mismatches

Answer 2

a) Increasing the concentration of magnesium (Mg2+), a cation

Question 3

How many bonds do A/U bonds make?

Answer 3

2-H bonds

Question 4

How many bonds do C/G bonds make?

Answer 4

3-H bonds

Question 5

What type of bonds are the most stable?

Answer 5

C/G

Question 6

Helicase

Answer 6

essential enzymes that are responsible for unwinding/melting duplex nucleic acid structures

Question 7

When DNA “melts,” which bonds are broken?

a) Glycosidic
b) Hydrogen
c) Phosphodiester

Answer 7

b) Hydrogen

Question 8

Which of the following is a substrate for DNA polymerase?

a) AMP
b) dATP
c) ATP
d) dAMP

Answer 8

b) dATP

Question 9

What is the 5’ end of DNA Synthesis synonymous with?

Answer 9

the phosphate group

Question 10

What is the 3’ end of DNA Synthesis synonymous with?

Answer 10

A hydroxyl

Question 11

Nucleotide base tautomerization:

a) has no effect on replication fidelity.
b) disrupts base pairing by changing hydrogen bond donors to acceptors, or vice versa.
c) only affects cytosine.
d) affects the glycosidic bond with ribose.

Answer 11

b) disrupts base pairing by changing hydrogen bond donors to acceptors, or vice versa.

Question 12

What type of ploymerase is Telomerase?

Answer 12

DNA

Question 13

What template is Telomerase associated with?

Answer 13

RNA

Question 14

DNA polymerase fails to recognize that an incorrect nucleotide has been incorporated, resulting in a mismatch. Which repair pathway will correct this mistake?

a) Base excision repair
b) Nucleotide excision repair
c) Mismatch repair
d) Direct repair by methyltransferases

Answer 14

c) Mismatch repair

Question 15

What is the only form of DNA in which you might find “hoogsteen bases”

Answer 15

Z-DNA

Question 16

DNA Polymerase

Answer 16

A DNA polymerase that is used to repair pathways

Question 17

T/F: A polymerase will fill in the gaps, and a ligase will seal it up.

Answer 17

True

Question 18

Tyrosine recombinase mechanism

Answer 18

A sequence-specific recombinase that uses tyrosine as its active site residue, and proceeds through two sequential single-strand breaks to form a Holliday junction intermediate.

Question 19

What components of RNA polymerase tell it what DNA sequences are “promoters”

Answer 19

Sigma factors

Question 20

T/F: A sigma factor links the RNA polymerase to specific stretches of DNA that serve as a promoter.

Answer 20

True

Question 21

T/F: The catalytic portion of RNA polymerase can bind without a sigma factor.

Answer 21

False. the catalytic portion would have no idea what sequences it should bind to and initiate transcription from.

Question 22

What can form thymine dimers?

Answer 22

Pyrimidines

Question 23

T/F: Purines can form thymine dimers

Answer 23

False

Question 24

Exonuclease

Answer 24

An enzyme that cleaves nucleotides one at a time from the end of a nucleic acid.

Question 25

Structure of Purines

Answer 25

Adenine and Guanine

Question 26

Structure of Pyrimidines

Answer 26

Cytosine and Thymine

Question 27

Ribozyme

Answer 27

exclusively made from RNA

Question 28

Telomerase

Answer 28

Telomerase extends the end of the DNA strand. Since it has an RNA template within itself, during DNA replication, telomerase uses the RNA template to bind DNA at the end of the chromosome. After that occurs, Telomerase then polymerizes the end of the DNA strand using the RNA within itself as the template.

Question 29

Nucleotides

Answer 29

building blocks of nucleic acid polymers

Question 30

What are nucleotides comprised of?

Answer 30

A base, deoxyribose, and PO4

Question 31

T/F: Nucleic Acids can be single-stranded or multi-stranded

Answer 31

True

Question 32

Where would you find nucleotides in both the syn and anti-conformation?

Answer 32

Z-form double-stranded DNA

Question 33

B- form DNA

Answer 33

C2' endo conformation puts the phosphates further apart