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Flashcards in 2.06 Nucleic Acids Deck (49)
1

Polydeoxyribonucleotide

DNA

2

DNA is deoxygenated at ___

C-2

3

Sugar + nitrogen base

Nucleoside

4

Phosphodiester bond is formed between ____

carbon and oxygen

5

In nucleoside, nitrogen bases bound to _____ of the sugar

C-1

6

Bonds containing the -COOC group

Ester bond

7

Bonds between complementary nitrogen bases

Hydrogen bonding

8

Cytosine-Guanine has __ H-bonds

3

9

Adenine-Thymine has __ H-bonds

2

10

Chargaff's rule
Determine the percentage of cytosine molecules in a double-stranded DNA given that 32% are adenosine molecules.

18%
A=T=32%
100% - (A+T) = 100 - (32% + 32%) = 36% = C+G
C+G = 36%
Since C=G; then C = 36%/2 = 18%

11

Polymer of deoxyribonucleoside monophosphates covalently linked by 3'->5'-phosphodiester bonds

DNA

12

By convention, the bases located along the resulting deoxyribose-phosphate backbone are written in sequence from __ end of the chain to the __ end.

5'; 3'

13

The end with the free phosphate

5'-end

14

The end with the free hydroxyl

3'-end

15

The chains are paired in an _____ manner, 5'-end of one strand is paired with the 3'-end of the other strand

antiparallel

16

The spatial relationship between the two strands in the helix creates _____ that provide access for the binding of regulatory proteins to their specific recognition sequences along the DNA chain

Major and minor grooves

17

Disruption of the H-bonds can occur in the laboratory by these treatments

Chemicals
Heat
Decrease in salt concentration
(change in pH of the DNA solution - Lipincotts)

18

When DNA is heated, the temperature at which one half of the helical structure is lost is defined as the _____

Melting temperature

19

Loss of helical structure in DNA

Denaturation

20

Complementary DNA strands can reform the double helix by the process called ______

Renaturation

21

True/False
In denaturation, phosphodiester bonds are broken by the treatment.

False
H-bonds are broken during denaturation.

22

True/False
DNA that contains high concentrations of A and T denatures at a lower temperature than G- and C-rich DNA.

True
Because there are three H-bonds between G and C and only two between A and T

23

3 major structural forms of DNA

B, A, Z form

24

Right-handed helix with 10 residues per 360deg turn of the helix, and with the planes of the bases are perpendicular to the helical acis

B form

25

Produced by moderately dehydrating the B form
A right-handed helix with 11 base pairs per turn and the planes of the base pairs are tilted 20deg away from the perpendicular to the helical axis

A form

26

Left-handed helix that contains 12 base pairs per turn
Deoxyribose-phosphate backbone zigzags

Z form

27

Structural form of the double helix described by Watson and Crick in 1953

B form

28

3 major types of RNA that participate in the process of protein synthesis

rRNA, tRNA, mRNA

29

Found in association with several proteins as components of the ribosomes

rRNA

30

Smallest of the three major types of RNA molecules

tRNA

31

The most heterogeneous type of NRA in size and base seqence

mRNA

32

Polyhydroxyribonucleotide

RNA

33

Associated with ribosomes

rRNA

34

70s is present only in _____ while 80s is present only in _____

Prokaryotes
Eukaryotes

35

Adapter molecule

tRNA

36

Cloverleaf shape
Each species holds a single amino acid

tRNA

37

Extensive intrachain base pairing
Contains unusual bases

tRNA

38

Template in translation

mRNA

39

Usually found in eukaryotes

sRNA
small RNA

40

Different subtypes of sRNA

small nuclear RNA (snRNA)
micro RNA (miRNA)
small interfering RNA (siRNA)

41

RNA processing
Involved in gene regulation

snRNA

42

mRNA regulation
Regulates speed of creation of new RNA
Inhibition of gene expression

siRNA

43

Inhibition of gene expression

miRNA

44

Introduced when the DNA double helix is twisted

Supercoil

45

The greater the number of supercoils, the _____ the stress or torsion

Greater

46

Stabilization of double helix is via

Hydrophobic interaction between stacked nitrogenous bases
Van der waals forces
H-bonds between the nitrogenous base complementary pairing

47

Composed of a nitrogenous base, a pentose monosaccharide, and one, two or three phosphate gouprs

Nucleotide

48

Purine bases

Adenine
Guanine
(Para matandaan: PuGA)

49

Pyrimidine bases

Thymine
Cytosine
Uracil