DNA replication Flashcards
DNA replication occurs during mitosis in which phase?
S phase in the interphase of the cell
the old DNA is called?
parental DNA
the new DNA is called?
daughter DNA
what happens in conservative replication?
the parental dsDNA remains as-is while an entirely new ds genome is created
what happens in dispersive replication?
both copies of genomes were compose of scattered pieces of new and old DNA
what happens in semiconservative replication?
after replication, one strand of new double helix is parental and one strand is daughter
DNA replication is what?
SEMICONSERVATIVE
to begin replication, the double helix must be uncoiled by what enzyme?
helicase by ATP hydrolysis to break the hydrogen bonds
what location does the helicase begin unwinding at?
origin of replication (ORI) - the helicase scans the chromosome until they find the correct spot to initiate DNA replication
when helicase unwinds the helix, tension is created downstream, what enzymes help this and how?
topoisomerases, which cut one or both stands and unwrap the helix to release the excess tension
ssDNA is less stable than dsDNA, what protein protects DNA that has been unpackaged in preparation for replication and help keep the strand separate?
single-strand binding protein (SSBPs)
the separated strands after the helicase unwinds them, what are they referred to?
open complex - replication then begins
primase sythesizes a template strand for?
DNA polymerase enzyme cannot start a new DNA chain from scratch and it can only add nucleotides to an existing nucleotide chain
DNA pol works by?
catalyzing the elongation of the daughter strand using the parental template, and elongate the primer by adding dNTPs to its 3’ end
during elongation, the daughter strand is made 5’ to 3’ and the two strands end up antiparallel thus the template must be read?
3’ to 5’
