Replication Flashcards
Replication
synthesis of DNA from DNA
What direction doe the DNA strand read?
5’-3’
In replication, there is one old strand and one new strand, this is said to be
semi-conservative
What enzyme unwinds the DNA helix and separates the strands, forming the replication fork at the origin?
DNA helicase
How do the exposed strands stay stable after they unwind from the opposite strand?
single stranded binding proteins
In what direction does DNA polymerase synthesize DNA?
5’-3’
What does DNA polymerase need in order to start synthesizing?
RNA primase
Leading strand
The strand that synthesizes away from the origin of the replication fork. continuous replication
Lagging strand
the strand that replicates in the direction of the replication fork. discontinuous replication
Okazaki Fragments
The lagging strand has to keep being synthesized in fragments because it is going towards the replication fork and needs to keep going back.
What replaces the primer?
DNA polymerase 1
What seals up the phosphodiester backbone?
DNA ligase
What does topoisomerase do?
releaves tension of twist as it unwinds by cutting the backbone and resealing it.
What happens when there is not enough room to lay prime on 5’ end of lagging strand?
telomerase will take 3’ end of 5’-3’ and extend so that daughter strand an keep laying down primer and don’t loose and genetic material
What is the energy for replication?
nucleosidetriphosphates
