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DNA Replication

When replication happens, DNA polymerase, meselson & stahl, roles of accessory proteins, synthesis of DNA on leading strand, synthesis on DNA on lagging strand, diagram of process

When replication happens, DNA polymerase, meselson & stahl, roles of accessory proteins, synthesis of DNA on leading strand, synthesis on DNA on lagging strand, diagram of process


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Cartes-fiches 11
Langue English
Catégorie Biologie
Niveau Université
Crée / Actualisé 05.01.2020 / 13.01.2020
Attribution de licence Non précisé
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When does replication take place in eukaryotes and prokaryotes?

DNA replication in eukaryotes in S-Phase and prokaryotes replicate constantly

DNA Polymerase (role, how does it work)

DNA Polymerase is an enzyme that synthesizes DNA molecules from the leading and lagging strand

5' to 3' prime polymerase activity -> leading and lagging strand (lagging strand are sequences called okazaki fragments)

ALWAYS starts at a free 3' OH group!

DNA Helicase 

Unwinds the double helix into two single strands (leading & lagging strands), which act like two templates by breaking hydrogen bonds between bases 

RNA Primer

DNA Polymerase can extend chains but cannot start them (doesn't know where to start). The primer is the starting point ((a short chain of nucleotides that binds to the template)

DNA Primase 

DNA Primase binds to template strand and snythesizes RNA Primer (for DNA Polymerase)

Topoisomerase 

Relaxes helix and reduces torsion, that helicase can unwind the helix easily

Ligase 

Repares and connects DNA fragments 

Single strandend binding protein

Keeps the single DNA strands stable and separate from each other after the helicase undwinded the helix. DNA Polymerase can access the right sequences better