Enzymes
Two repair strategies for double-stranded breaks
What is non homologous end joining and homologous recombination?
Strand synthesized from the 5' to the 3' end
What is the leading strand
This is the enzyme that adds new nucleotide bases to the parent or template strand to form a new DNA strand
What is DNA Polymerase
Damage resulting in spontaneous loss of an amino group from cytosine to produce uracil
What is deamination?
Strand synthesized from the 3' to 5' end
What is the lagging strand
Two catalytic domains of DNA polymerase
What are the polymerizing and editing domains?
Joins Okazaki fragments together
What is DNA Ligase?
The first step to DNA damage repair
What is Damaged DNA is recognized and removed by nucleases
Discontinuous replication occurs in this strand
What is the lagging strand?
Disorder caused by faulty DNA repair
What is xeroderma pigmentosum?
RNA polymerase that synthesizes RNA primer required for initiation of DNA replication
What is Primase?
100 to 2000 nucleotide fragments formed in discontinuous replication
What are Okazaki fragments?
The second step to DNA damage repair
Repair DNA polymerase binds free 3’ OH of cut DNA strand – fills gap
Forms Okazaki fragments during replication
What is the lagging strand
Produces breaks in the DNA molecules to prevent supercoiling and knot formation during replication, then rejoins
What is topoisomerase?
Y-shaped junction that forms at site where DNA is being replicated
What is a replication fork?
Two steps involved in DNA mismatch repair
What is 1. Removal of a portion of DNA strand containing mismatch 2. Resynthesize missing DNA
Strand synthesized in a bidirectional fashion?
What is BOTH!
Damage resulting in covalent linkage between two adjacent pyrimidine bases
What are thymine dimers?