- Shuffle
Toggle OnToggle Off
- Alphabetize
Toggle OnToggle Off
- Front First
Toggle OnToggle Off
- Both Sides
Toggle OnToggle Off
Front
How to study your flashcards.
Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key
Up/Down arrow keys: Flip the card between the front and back.down keyup key
H key: Show hint (3rd side).h key
PLAY BUTTON
PLAY BUTTON
22 Cards in this Set
- Front
- Back
|
Why do different conformations in sugars occur?
|
Different conformations in sugars because they are enveloped not flat
|
|
What does helicase do?
|
seperate DNA strands
|
|
What does primase do?
|
supplies RNA primer for DNA polymerase
|
|
What does DNA polymerase do and in what direction?
|
DNA repliation, 5-3 reads 3-5
|
|
what does topoisomerase do?
|
relieve stress that replication produces on DNA winding
|
|
what does ligase do?
|
seals phosphodiester bonds
|
|
What does DNA polymerase activity require?
|
DNA template
Primer with free 3' OH |
|
what is the key reaction of DNA polymerase?
|
nucleophilic attack by 3' OH oh pyrophosphate bond
|
|
What helps align substrates during replication?
|
2 Mg2+ ions in the DNA polymerase active site
|
|
What energy does DNA helicase use?
|
one domain hydrolyzes ATP to produce energy
second domain binds the DNA, sliding along seperating DNA |
|
How does topoisomerase I work?
|
1) cutting one strand
2) allowing rotation about the remaining strand 3) reseal the break |
|
what energy does topoisomerase use?
|
thermodynamically favorable, NOOOOOO ATP needed
inhibited by some cancer drugs (ex. irinotecan) |
|
How does topoisomerase II work?
|
1) cuts both strands
2) passing the rest of molecule through break 3) resealing the break |
|
What energy oes topoisomerase II use?
|
ATP
human version s inhibited by some cancer drugs (ex. Etoposide bacterial versions targeted by some antibiotics |
|
how does DNA replication begin?
|
RNA primer laid down by primase
|
|
During DNA replication the DNA gets smaller; how is this problem combated?
|
telemeres
|
|
What is the most common form of mutation?
|
substitution
|
|
what types of mutations cause frame shifts?
|
deletions and insertions
|
|
What is a synonymous mutations?
|
also called silent mutation, the substitution still codes for same amino acid
|
|
what are the five ways mutations can occur
|
1) tautomerization
2) chemical reactions 3) compounds that intercalate (slip in) between adjacent base pairs causing insertion/deletion (ex. ethidium bromide in electrophoresis) 4) detoxification enzymes can convert some compounds to mutagens 5) UV-induced linkage of adjacent pyrimidine residues in a DNA strand (THYMINE DIMER) |
|
What are the three ways to repair DNA?
|
1) base excision repair
2) direct repair (ex. photochemical cleavage of pyrimidine dimers) 3) nucleotide excision repair |
|
What are the steps of nucleotide excision repair?
|
1) specialized enzymes remove nucleotides adjacent to an incorrect pairing
2) the correct nucleotides are filled back in by DNA polymerase and DNA ligase acting as they always do |
