Midterm 2

Question 1

Helicases

Answer 1

An enzyme that untwists the double helix at the replication forks

Question 2

Topoisomerase

Answer 2

Enzyme which helps relieve the strain and pressure of the untwisting double helix

Question 3

Primer

Answer 3

A short nucleic acid sequence that provides a starting point for DNA synthesis.

Question 4

Primase

Answer 4

Enzyme which acts as a primer

Question 5

DNA Polymerase

Answer 5

An enzyme that catalyzes the synthesis of new DNA by adding nucleotides to the 3′ end of a preexisting chain.

Question 6

Okazaki Fragment

Answer 6

Short sequences of DNA nucleotides which are synthesized discontinuously and later linked together by the enzyme DNA ligase

Question 7

DNA Ligase

Answer 7

Joins the fragments together after RNA nucleotides have been replaced with DNA nucleotides

Question 8

Telomere

Answer 8

DNA–protein structures found at both ends of each chromosome, protect the genome from nucleolytic degradation, unnecessary recombination, repair, and interchromosomal fusion. Telomeres therefore play a vital role in preserving the information in our genome.

Question 9

What are the Purines

Answer 9

Adenine (A) and Guanine (G)

Question 10

What are the pyrimidines?

Answer 10

Cytosine (C), Thymine (T) and Urasil (U)

Question 12

How many rings do purines have?

Answer 12

2

Question 13

How many rings do pyrimidines have?

Answer 13

1

Question 14

What number carbon of atoms is the nitrogenous base bonded to?

Answer 14

1’

Question 15

What number carbon of atoms is the next nucleotide bonded to?

Answer 15

3’