DNA Flashcards
1
Q
dna vs rn
A
rna has oh
dna weight is 10^9
- directional
2
Q
base hyrolysis, dna
A
- can’t hydrolyze dna with base
- rna can
- need 2’ oH for reaction
- breaks phosphodiester bonds
3
Q
acid hydrolysis
A
- midl acid removes purinne base only and backbone ok
- strong acid destroys
4
Q
exo nuclease
A
- attack end of molcule and break off nucleotides
- some for 3’ other for 5’
5
Q
endonuclease
A
- attack links within chain
- restriction enzyme: recognizes specific nucleotides in DNA
6
Q
chargaff
A
a = t ( 2 bonds)
7
Q
b dna
A
right hand helix
8
Q
a dna
A
right hand but bases are tilted
9
Q
z dna
A
left hand helix
10
Q
supercoil
A
package dna innto double helix and closed circular loop
11
Q
hyperchromic effect
A
dna absorbs uv at 260 nm due to nitrogen base
- dna is neatured, then decrease in abs (more free bases to absorb rad instead of bonded bases only)
- a and t are the most
- curve boi
12
Q
melting point of dna
A
- heat breaks h bonds
- the tm is point where dna is 1/2 denatured
- more gc is higher tm (linear)
13
Q
buoyant density
A
- cscl in centrifuge forms a gradient with dense on the bottom
- dna will move until dna density = density cscl
- can pierce the tube and drain to collect fractions
- more cg is more dense (linear)
