DNA Replication Flashcards
Bacteria have
circular and relatively smaller genomes
Bacteria contain ___ origin of replication (oriC)
one
replication forks
DNA is unwound and these are the points in which replication is happening
Replication for originally appears at theorigin of replication and the spreads out ____ resulting in ___ replication forks
Bidirectionally
2
Polymerase
formation of a polymer, repeating molecules
DNA polymerases use energy from dNTPS to build
complementary sequence of DNA
Two terminal phosphates are cleaved releasing pyrophosphate and incorporating a
dNMP into the DNA molecule
Chain elongation in the
5’-3’ direction
DNA polymerase III
DNA synthesis during replication and proofreading
DNA polymerase I
Filling gaps and removing primer, DNA repair
Active forms of DNA polymerase III is called
holoenzyme
The length of DNA that is replicated is referred to as the
replicon
holoenzyme- core enzyme with catalytic function
5’-3’ polymerization
3’-5’ exonuclease
Sliding clamp loader and DNA clamp
processivity and ATP hydrolysis
___ is needed to start synthesis for DNA polymerase
primer
RNA primers must be removed and replaced with
DNA
Gaps in backbone must be
sealed
DNA helicase continuously separates
DNA strands
Sing-Stranded binding proteins (SSBs)
bind and coat ssDNA molecules to protect ssDNA and inhibit dsDNA from reforming
supercoiling
coiling tension
DNA topioisomerase (gyrase)
cleave the DNA backbone using ATP
An RNA polymerase (primase) adds a short ___ to which DNA pol III can add DNA for replication
RNA primer
okazaki fragments are present on the
discontinuous lagging strand
DNA pol I removes the
RNA primer and synthesizes new DNA
DNA ligase joins together
okazaki fragments repairing the gap in the backbone
Telomeres
protect the ends from nucleases
Telomerase
extend the length of dsDNA
Is telomerase active in most cells?
no
