Midterm 2 Flashcards
Helicases
An enzyme that untwists the double helix at the replication forks
Topoisomerase
Enzyme which helps relieve the strain and pressure of the untwisting double helix
Primer
A short nucleic acid sequence that provides a starting point for DNA synthesis.
Primase
Enzyme which acts as a primer
DNA Polymerase
An enzyme that catalyzes the synthesis of new DNA by adding nucleotides to the 3′ end of a preexisting chain.
Okazaki Fragment
Short sequences of DNA nucleotides which are synthesized discontinuously and later linked together by the enzyme DNA ligase
DNA Ligase
Joins the fragments together after RNA nucleotides have been replaced with DNA nucleotides
Telomere
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.
What are the Purines
Adenine (A) and Guanine (G)
What are the pyrimidines?
Cytosine (C), Thymine (T) and Urasil (U)
How many rings do purines have?
2
How many rings do pyrimidines have?
1
What number carbon of atoms is the nitrogenous base bonded to?
1’
What number carbon of atoms is the next nucleotide bonded to?
3’