DNA replication
What is the enzyme responsible for breaking the bonds connecting the two strands?
Helicase
The point at which the helicase is working to unzip the molecule is called a _______.
Replication fork
DNA strands can only be assembled in what direction?
5' to 3'
What are the two mechanisms for replication?
Continuous and discontinuous synthesis
Continuous synthesis happens on the _____ strand. DNA primase adds an ________ and ___________ adds nucleotides to the 3' end of the leading strand. __________ then replaces the primer with nucleotides.
Leading, RNA primer, DNA polymerase 3, DNA polymerase 1
Discontinuous synthesis occurs on the _______ strand. DNA primase adds an ___________ in front of the 5' end of the lagging strand and ______________ adds nucleotides. _________ replaces the primer, and finally ________ attaches the _____ fragment to the lagging strand.
Lagging strand, RNA primer, DNA Polymerase 3, DNA Polymerase 1, DNA ligase, Okazaki
What is the function of helicase?
Unwinds double helix at replication fork
What is the function of the DNA primase?
Synthesizes the RNA primer
What is the function of the RNA primer?
Marks the beginning of the replication process.
What does DNA Polymerase 1 do vs DNA Polymerase 3?
1: Removes the RNA primer at the end of replication and replaces it with DNA nucleotides.
2: Synthesizes the new strand by catalyzing the addition of nucleotides in a 5' to 3' direction.
What does DNA ligase do?
Joins the ends of the DNA segments and Okazaki fragments.
What do single stranded binding proteins do?
Keeps bases from reforming H bonds between them after helicase action.
How does DNA polymerase 3 do DNA proofreading?
Checks for accuracy in the daughter strand it is synthesizing. Can regonize mismatched nucleotides and remove it from the 3' end of the daughter strand.