Kapitel 6 Flashcards
Enzyme that reseals nicks that arise in the backbone of a DNA molecule; in the laboratory - can be used to join together two DNA fragments.
DNA ligase
Collective term for the enzymatic processes that correct deleterious changes affecting the continuity or sequence of a DNA molecule.
DNA repair
The process by which a copy of a DNA molecule is made.
DNA replication
Mechanism by which double-strand breaks in a DNA molecule can be repaired flawlessly; uses an undamaged - duplicated - or homologous chromosome to guide the repair. During meiosis - the mechanism results in an exchange of genetic information between the maternal and paternal homologs.
homologous recombination
At a replication fork - the DNA strand that is made discontinuously in short separate fragments that are later joined together to form one continuous new strand.
lagging strand
At a replication fork - the DNA strand that is made by continuous synthesis in the 5′-to-3′ direction.
leading strand
Mechanism for recognizing and correcting incorrectly paired nucleotides—those that are noncomplementary.
mismatch repair
A randomly produced - permanent change in the nucleotide sequence of DNA.
mutation
A quick-and-dirty mechanism for repairing double-strand breaks in DNA that involves quickly bringing together - trimming - and rejoining the two broken ends; results in a loss of information at the site of repair.
nonhomologous end joining
Short length of DNA produced on the lagging strand during DNA replication. Adjacent fragments are rapidly joined together by DNA ligase to form a continuous DNA strand.
Okazaki fragment
An RNA polymerase that uses DNA as a template to produce an RNA fragment that serves as a primer for DNA synthesis.
primase
The process by which DNA polymerase corrects its own errors as it moves along DNA.
proofreading
Y-shaped junction that forms at the site where DNA is being replicated.
replication fork
Enzyme that elongates telomeres - synthesizing the repetitive nucleotide sequences found at the ends of eukaryotic chromosomes.
telomerase
A molecular structure that serves as a pattern for the production of other molecules. For example - one strand of DNA directs the synthesis of the complementary DNA strand.
template
