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Flashcards in DNA Chemistry Deck (26)
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1
Q
What 4 nitrogenous bases are used in DNA?
A
Adenine, guanine, cytosine, and thymine
2
Q
What 4 nitrogenous bases are used in RNA?
A
Adenine, guanine, cytosine, and uracil
3
Q
What is the shape of a purine base?
A
Double ring
4
Q
What is the shape of a pyrimidine base?
A
single ring
5
Q
What does acid form when hydrolyzing DNA and RNA?
A
purine bases, pyrimidine nucleosides, sugar moiety, and phosphates
6
Q
What does base hydrolysis form with DNA and RNA?
A
DNA is resistant to base hydrolysis.
RNA forms nucleoside monophosphate
7
Q
What direction are the DNA double helixes?
A
Right
8
Q
Where are polar groups in the DNA helix?
A
Phosphates project outward to interact with proteins. Negatively charged phosphates make complex with Na, Ca, and K to stabilize the helix
9
Q
Where are non-polar groups in the DNA helix?
A
The interior of the molecule because they are extremely hydrophobic
10
Q
What force contributes greatly to helix stability due to the closeness of the nitrogen bases
A
Van der Waals
11
Q
What base pairing has a stronger bond: AT or GC?
A
GC due to the double bonds
12
Q
What is the distance for (1) one complete turn and (2) between stacked nitrogenous bases?
A
1) 3.4nm
2) 0.34 nm
13
Q
How many bases are in each conformation of DNA?
A
A—11 (tilted bases relative to long axis)
B—10
C—9 (probably doesn't occur in vivo)
Z—12 (is a left helix)
14
Q
Hypochromic effect
A
Tightly stacked bases are less likely to be altered by UV rays
15
Q
Southern Blotting
A
DNA sample, used for gene structure/complexity
16
Q
Northern Blotting
A
RNA sample, used to measure mRNA levels
17
Q
Western Blotting
A
Protein sample
18
Q
What is necessary to create a DNA library
A
Vectors
19
Q
Ligation
A
Joining of DNA via phosphodiester bonds
20
Q
What allows DNA to be packaged into a bacteriophage protein coat?
A
COSmids
21
Q
Non repetitive DNA sequence frequency
A
Usually where transcription takes place
22
Q
Why are histones base proteins?
A
Have high levels of arginine and lysine
23
Q
Octamer
A
The core of 8 histones that DNA wraps around
24
Q
From which histone are solenoid structures formed?
A
Histone 1
25
Q
What does the acetylation or phosphorylation of histone amino acids do?
A
Decreases histone to DNA interactions, relaxing the chromatin
26
Q
What type of plasmid DNA travels the fastest in agarose gel electrophoresis?
A
Tightly bound DNA (supercoiled)