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Flashcards in DNA Chemistry Deck (26):
1

What 4 nitrogenous bases are used in DNA?

Adenine, guanine, cytosine, and thymine

2

What 4 nitrogenous bases are used in RNA?

Adenine, guanine, cytosine, and uracil

3

What is the shape of a purine base?

Double ring

4

What is the shape of a pyrimidine base?

single ring

5

What does acid form when hydrolyzing DNA and RNA?

purine bases, pyrimidine nucleosides, sugar moiety, and phosphates

6

What does base hydrolysis form with DNA and RNA?

DNA is resistant to base hydrolysis.
RNA forms nucleoside monophosphate

7

What direction are the DNA double helixes?

Right

8

Where are polar groups in the DNA helix?

Phosphates project outward to interact with proteins. Negatively charged phosphates make complex with Na, Ca, and K to stabilize the helix

9

Where are non-polar groups in the DNA helix?

The interior of the molecule because they are extremely hydrophobic

10

What force contributes greatly to helix stability due to the closeness of the nitrogen bases

Van der Waals

11

What base pairing has a stronger bond: AT or GC?

GC due to the double bonds

12

What is the distance for (1) one complete turn and (2) between stacked nitrogenous bases?

1) 3.4nm
2) 0.34 nm

13

How many bases are in each conformation of DNA?

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

Hypochromic effect

Tightly stacked bases are less likely to be altered by UV rays

15

Southern Blotting

DNA sample, used for gene structure/complexity

16

Northern Blotting

RNA sample, used to measure mRNA levels

17

Western Blotting

Protein sample

18

What is necessary to create a DNA library

Vectors

19

Ligation

Joining of DNA via phosphodiester bonds

20

What allows DNA to be packaged into a bacteriophage protein coat?

COSmids

21

Non repetitive DNA sequence frequency

Usually where transcription takes place

22

Why are histones base proteins?

Have high levels of arginine and lysine

23

Octamer

The core of 8 histones that DNA wraps around

24

From which histone are solenoid structures formed?

Histone 1

25

What does the acetylation or phosphorylation of histone amino acids do?

Decreases histone to DNA interactions, relaxing the chromatin

26

What type of plasmid DNA travels the fastest in agarose gel electrophoresis?

Tightly bound DNA (supercoiled)