Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
|
replication bubble |
a long strand of A:T pairs that form a localized zone of denaturation -essential first step in replication of DNA |
|
|
Prok: DNA Polymerase |
-synthesizes 5'-->3' -require a free 3'-hydroxyl group |
|
|
lagging strand |
-strand that extends 3'-->5' -grows by the synthesis of Okazaki fragments and the subsequent covalent bonding of these short fragments |
|
|
DNA Ligase |
-links Okazaki fragments -cataylzes the covalent closure of nicks in DNA by using energy from NAD or ATP |
|
|
RNA Polymerase |
-cataylzes the synthesis of RNA molecules from DNA templates -initiates the synthesis of new RNA chains at specific sites on the DNA |
|
|
each new DNA chain is initiated by a short.. |
RNA primer synthesized by DNA primase |
|
|
DNA polymerase III |
catalyzes the semiconservative replication of the chromosome -catalyzes the addition of deoxyribonucleotides to RNA primers -terminates an Okazaki fragment when it bumps into the RNA primer of the preceding Okazaki fragment |
|
|
DNA Polymerase I |
-excises and replaces RNA primers with DNA chains -has 2 exonuclease activities |
|
|
DNA polymerase I exonuclease activity |
-5-->3 excises the RNA primer and replaces the RNA with a DNA chain -3-->5 exonuclease activity cleaves off nucleotides from the 3' termini of DNA strands |
|
|
DNA helicase |
unwinds DNA using energy from ATP |
|
|
SSB protein |
after DNA is unwound, it has to be kept in an extended single strand state, so this protein coats the strains to maintain this |
|
|
DNA Topoisomerases |
the enzymes that provide the required axes of rotation during the replication of circular DNA molecules |
|
|
Top 1 and Top 2 |
1: removes supercoils from DNA one at a time oriduce temporary single strand breaks or nicks in DNA 2: produce transient double strand breaks in DNA and remove and introduce negative supercoils two at a time |
|
|
S phase |
dna replication occurs in S phase (g1, g, s, g2, mitosis) |
|
|
eukaryotes: replication protein |
equivalent to ssb protein in prokaryotes, keeps unwound strands in extended state |
