2.06 Nucleic Acids

Question 1

Polydeoxyribonucleotide

Answer 1

DNA

Question 2

DNA is deoxygenated at ___

Answer 2

C-2

Question 3

Sugar + nitrogen base

Answer 3

Nucleoside

Question 4

Phosphodiester bond is formed between ____

Answer 4

carbon and oxygen

Question 5

In nucleoside, nitrogen bases bound to _____ of the sugar

Answer 5

C-1

Question 6

Bonds containing the -COOC group

Answer 6

Ester bond

Question 7

Bonds between complementary nitrogen bases

Answer 7

Hydrogen bonding

Question 8

Cytosine-Guanine has __ H-bonds

Answer 8

3

Question 9

Adenine-Thymine has __ H-bonds

Answer 9

2

Question 10

Chargaff’s rule

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

Answer 10

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

Question 11

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

Answer 11

DNA

Question 12

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

Answer 12

5’; 3’

Question 13

The end with the free phosphate

Answer 13

5’-end

Question 14

The end with the free hydroxyl

Answer 14

3’-end

Question 15

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

Answer 15

antiparallel

Question 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

Answer 16

Major and minor grooves

Question 17

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

Answer 17

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

Question 18

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

Answer 18

Melting temperature

Question 19

Loss of helical structure in DNA

Answer 19

Denaturation

Question 20

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

Answer 20

Renaturation

Question 21

True/False

In denaturation, phosphodiester bonds are broken by the treatment.

Answer 21

False

H-bonds are broken during denaturation.

Question 22

True/False

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

Answer 22

True

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

Question 23

3 major structural forms of DNA

Answer 23

B, A, Z form

Question 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

Answer 24

B form

Question 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

Answer 25

A form

Question 26

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

Answer 26

Z form

Question 27

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

Answer 27

B form

Question 28

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

Answer 28

rRNA, tRNA, mRNA

Question 29

Found in association with several proteins as components of the ribosomes

Answer 29

rRNA

Question 30

Smallest of the three major types of RNA molecules

Answer 30

tRNA

Question 31

The most heterogeneous type of NRA in size and base seqence

Answer 31

mRNA

Question 32

Polyhydroxyribonucleotide

Answer 32

RNA

Question 33

Associated with ribosomes

Answer 33

rRNA

Question 34

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

Answer 34

Prokaryotes | Eukaryotes

Question 35

Adapter molecule

Answer 35

tRNA

Question 36

Cloverleaf shape | Each species holds a single amino acid

Answer 36

tRNA

Question 37

Extensive intrachain base pairing | Contains unusual bases

Answer 37

tRNA

Question 38

Template in translation

Answer 38

mRNA

Question 39

Usually found in eukaryotes

Answer 39

sRNA | small RNA

Question 40

Different subtypes of sRNA

Answer 40

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

Question 41

RNA processing | Involved in gene regulation

Answer 41

snRNA

Question 42

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

Answer 42

siRNA

Question 43

Inhibition of gene expression

Answer 43

miRNA

Question 44

Introduced when the DNA double helix is twisted

Answer 44

Supercoil

Question 45

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

Answer 45

Greater

Question 46

Stabilization of double helix is via

Answer 46

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

Question 47

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

Answer 47

Nucleotide

Question 48

Purine bases

Answer 48

Adenine Guanine (Para matandaan: PuGA)

Question 49

Pyrimidine bases

Answer 49

Thymine Cytosine Uracil