Unit 6, Topic 2: Replication Flashcards
specific nucleotide sequences that signal the beginning of replication
origins of replication
Y-shaped structure formed during initiation of replication
Replication fork
during replication, this enzyme helps to open up the DNA helix by breaking the hydrogen bonds
helicase
enzyme that prevents overwinding of DNA when DNA replication is taking place
Topoisomerase
enzyme that synthesizes the RNA primer; the primer is needed for DNA pol to start synthesis of a new DNA strand
Primase
short stretch of nucleotides that is required to initiate replication; in the case of replication, the primer has RNA nucleotides
Primer
the enzyme required for DNA synthesis
DNAP III
enzymes required for DNA repair
DNAP I & II
strand that is synthesized continuously in the 5’-3’ direction which is synthesized in the direction of the replication fork
Leading strand
during replication, the strand that is replicated in short fragments and away from the replication fork
lagging strand
DNA fragment that is synthesized in short stretches on the lagging strand
Okazaki fragments
enzyme that catalyzes the formation of a phosphodiester linkage between the 3’ OH and 5’ phosphate ends of the DNA
DNA ligase
DNA at the end of linear chromosomes
Telomere
enzyme that degrades nucleic acids
Nuclease
enzyme that contains a catalytic part and an inbuilt RNA template; it functions to maintain telomeres at chromosome ends
Telomerase
type of repair mechanism in which mismatched bases are removed after replication
mismatch repair
In which stage of the cell cycle does DNA replicate?
S phase of interphase
If an error occurs in DNA replication, how is it fixed?
DNA polymerase proofreading
In which model do both copies of DNA have double-stranded segments of parental DNA and newly synthesized DNA interspersed?
dispersive model
In which model does the parental DNA remain together, and the newly formed daughter strands are together?
conservative model
In which model do each of the two parental DNA strands act as a template for new DNA to be synthesized?
semi-conservative model
after replication, each double-stranded DNA includes one parental or “old” strand and one “new” strand.
