DNA Replication Flashcards
What is replication?
duplication of DNA
When does DNA replication occur?
S phase in interphase of the cell cycle
What does it mean for DNA replication to be semiconservative?
new daughter strands are synthesized using the parental DNA as a template to copy from; each new daughter strand is perfectly complementary to the parental strand
What is the helicase?
enzyme that unwinds, separates and stabilizes double stranded DNA
What is the place that helicase begins to unwind the DNA?
ORI; origin of replication
What protein in bacteria will find the ORI?
DnaA
What are topoisomerases?
enzymes that cut one or both double strands and unwrap the helix, releasing the excess tension caused by the helicase
What are SSBPs?
single-strand binding proteins; protect the DNA that has been unpackaged and help keep the strands separated
What is the open complex?
when the two strands are separated
What must occur prior to replication of DNA?
RNA primer must be synthesized for each template strand
What enzyme/proteins is involved in creating the RNA primer?
protein complex = primosome
enzyme = primase
What catalyzes the elongation of the daughter strand?
DNA polymerase
What complex is DNA polymerase a part of?
replisome
What is the thermodynamic driving force for polymerization reaction?
removal and hydrolysis of pyrophosphate from each dNTP added to the chain
Which direction does polymerization occur?
5’ to 3’