Lecture 13: DNA Replication Flashcards
Binds to the origin and pulls strands apart
origin binding protein
Moves down the template 5’-3’ direction and uses ATP to break H bonds
Helicase
Makes the RNA primer (makes phosphodiester bonds)
Primase
keeps the template strands apart
single strand binding protein
extends RNA primer
DNA Pol III
removes and replaces RNA primer
DNA Pol I
Connects Okazaki fragments
ligase
What are the steps of DNA replication?
- Yank DNA apart and lay down RNA primer
- Add DNA nucleotides by DNA Pol III
- Remove RNA primer
- Ligate Okazaki fragments
Bi-directional DNA replication with 2 replication forks
Replication on circular prokaryotic chromosomes
In replication, in circular prokaryotes, the _______ strand is going toward the origin
lagging
In replication, in circular prokaryotes, the _______ strand is going away from the origin
leading
What direction does helicase move on the template or parental strand?
5’-3’ direction
What is the energy source it uses to break H bonds?
ATP
What bond does SSB keep from reforming?
H Bonds
Where does helicase get its energy to perform its main function?
ATP
What were the nucleotides before they were added to the new strand?
Nucleoside Triphosphate
Why do Nucleotides start as Nucleoside Triphosphates?
Provide energy by breaking off pyrophosphate and then broken down
______ is the RNA Pol involved in ___ _________ whereas ____ __________ is involved in transcription.
Primase; DNA Replication; RNA Polymerase
DNA replication is semiconservative; this should demonstrate why ____ ____ ____ is the enzyme that extends the RNA primer once it has been completed.
DNA Pol III
Adding DNA nucleotides by DNA Pol III
DNA replication
The ribonucleotide at the 5’ end of the RNA primer on the lagging strand is removed using the ____ __________ activity of ___ ____ _
5’-3’ exonuclease; DNA Pol I
DNA replication
removal of RNA primer
DNA Pol I continues to remove RNA primer using ____ exonuclease activity and fills with DNA
5’-3’
The bond is made by DNA ligase and requires ____ breakdown to drive the reaction
NAD+
