Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Botany > BIOCHEM LAB - Nucleic Acids > Flashcards

BIOCHEM LAB - Nucleic Acids Flashcards

1
Q

monomer unit of nucleic acids

A

nucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

NA carries a __ charge on the oxygen of the phosphate component

A

-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

not nutrient biomolecules because —

A

they can be biosynthesized

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

NA are branched or unbranched?

A

unbranched

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

a 5-carbon monosaccharide in ring form as heterocyclic hemiacetal derived from furan

A

PENTOSE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

has a deoxyribose sigar with OH group on 3’ position of sigar ring

A

DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

has a ribose sugar with OH group at 2’ and 3’ positions of sugar ring

A

RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

No NA, NO ___

A

Organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

blueprint of an organism is encoded in

A

NA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

nitrogen base is attached to the 1’ carbon of sugar through a what type of bond

A

glycosidic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

fused bicyclic base

A

purine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

monocyclic base, 6membered rin

A

pyrimidine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

purines are attached to sugar by what beta-glycosidic bond

A

N9 - C1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

pyrimidines are attached to sugar by what beta-glycosidic bond

A

N1-C1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

More susceptible to H hydrolysis due to greater dipositivity of glycosyl bonds

A

glycosidic bonds to purine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

IUPAC name of cytosine

A

2-oxo-4-aminopyrimidine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

IUPAC name of thymine

A

5-methyl-2,4-dioxopyrimidine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

IUPAC name of uracil

A

2,4-dioxopyrimidine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

bases that are planar

A

pyrimidine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

bases that are very nearly planar with a slight pucker

A

purine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

IUPAC name of adenine

A

6-aminopurine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

IUPAC name of guanine

A

2-amino-6-oxopurine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

most polar base

A

Guanine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

least polar base

A

thymine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

gives NA their acidic and anionic character

A

phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

phosphate is attached to what carbon atom

A

5’ c of the sugar component

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

type of bond between phosphate groups

A

phosphate anhydride or pyrophosphate bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

small proteins containing basic amino acids: lysine and arginine

A

histones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

in circular DNA, the type of hydrogen bonding is intra or inter

A

INTRA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

forms the solenoid supertstructure

A

DNA-histone complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

DNA-histone complex forms ____ structure when it undergoes coiling

A

solenoid supertstructure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Chromatinf iber is formed by

A

solenoid interaction with scaffold protein

undergoes compaction by folding and coiling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

short-lived NA

synthesized as the need arises

A

RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

mostly found in cytoplasm with non-histone proteins in ribosome

A

RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

found in nucleolus of nucleus where ribsomes are synthesized

A

rna

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

WHERE THE DNA IS ALSO FOUND

A

in mitochondria and chloroplast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

responsible for the 3d structure of DNA

A

James Watson and Francis Crick

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

xray diffraction data

A

Maurice Wilkins

Rosalind Franklin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

double-helical forms by which DNA exists

A

A B C D E H Z L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

natural DNA

most stable and dominant under physiological conditions

A

B-DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

handedness of B-DNA

A

right handed (2 helix)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

pitch of B-DNA

A

3.4 nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

rise of B-DNA

A

0.34 nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

helical diamtere of of B-DNA

A

2.0 nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

number of base pair per turn of of B-DNA

A

10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

has minor and major grooves and is found in the cells

A

B-DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

coiling od B-DNA is described as

A

plectonemic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

this NA may contain local regions of short complementary base-pairing

A

RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

NA that has a strong tendency to adopt a random coil conformation

A

RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

NA found in RER

A

RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

CHARGAFF’S RULES

Base composition of DNA ___ from one species to another

A

varies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

CHARGAFF’S RULES

DNA of closely related species have ___ base composition

A

similar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

CHARGAFF’S RULES

DNA of diff tissues of an organism have ___ base composition

A

same

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

CHARGAFF’S RULES

base composition of DNA (change or does not?) with age, nutritional, state etc

A

NOT CHANGE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

CHARGAFF’S RULES

the ratios of adenine to T and G-C were nearly

A

1.0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

CHARGAFF’S RULES

total number of purines in one strand is ____ to total number of pyrimides in complementary strand

A

same

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

structure which descirbes nucleotide base sequence

polarity of sugar backbone

A

primary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

by convention, sequences are written in what direction

A

5’ to 3’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

stabilizing factos in primary structure

A

covalent bonds
tautomerism
resonance energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

it is a phosphodiester bond bet nucleotide monomers

the main stabilizing factor

A

covalent bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

covalent PHOSPHODIESTER bonds are stable between what ph

A

pH 3 AND 12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

at extremes in pH, phosphodiester bonds are ___

A

HYDROLYZED resulting in scission or shearing of DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

stabilizing factor of primary struc that is pH dependent

A

tautomerism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

a stabilizing factor formed when nitrogen bases are stabilized by electron delocalization

A

tautomers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

what is formed when nitrogen bases are stabilized by electron delocalization

A

tautomers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

type of tautomer that is predominant and more stable

A

commone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

N bases are aromatic, which means they are

A

thermodynamically stable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

the higher resonance energy, __

A

more thermodynamically stable

69
Q

which type of base is more thermodynamically stable

A

purines

70
Q

degree or thermodynamic stability

A

A>G>C>U>T

71
Q

structure which descirbes the helical conformation of NA

A

secondary

72
Q

conformation that is more thermodynamicallys table

A

helical instead of random coil

73
Q

conseuqence of RNA being SS with regard t degree of secondary structure

A

lesser in degree than DNA

74
Q

stabilizing factors in secondary structure

A

complementary base-pairing via intermolecular HB in DNA or intra in RNA
base stacking via pi-pi complexation rxns

75
Q

T or F

E delocalization becomes more extensive when complementary bases are HB to each other

A

T

76
Q

Properties of DNA related to 2ndary structure

DNA is relatively stable but not inert. Why

A

strands separate during repli/transcrip

77
Q

Properties of DNA related to 2ndary structure

DNA solutions are viscous because

A
  1. rigidity of double helix

2. high length/diameter ratio

78
Q

Properties of DNA related to 2ndary structure

DNA is most stable and soluble in salt solutions with ___ high or low conc

A

HIGH

79
Q

salt solutions of less than ___ M would weaken HB

A

0.1 M

80
Q

effect caused by exposure of nitrogen bases

A

hyperchromic effect

81
Q

effect of hyperchromic effect to absorbance

A

increase in 260nm

82
Q

denaturation is reversible or irreversible?

A

reversible

83
Q

hyperchroic effect is caused by the

A

exposure of nitrogen bases caused by unstacking caused by Hbonds disruption caused by unwinding

84
Q

conformation of SS DNA after hyperchromic effect

A

random coil

85
Q

process by which denatured complementary strands of DNA can reform a duplex DNA structure

A

renaturation or annealing

86
Q

as DNA anneals, its absorbance will ______

A

decrease - causing hypochromic effect

87
Q

relationship of rate of renaturation to concentration of complementary strands

A

direct

88
Q

when does dna become less viscous

A

high temp

treatment with alkali

89
Q

temp at which dna dissociate or unwinds

A

80-90

90
Q

temp related denaturation

A

melting

91
Q

temp at which 50% of double helix is unwound

A

melting pt or transition temp

92
Q

Tm is determined using a

A

thermal denaturation curve
temperature profile
melting curve

93
Q

temp at which dna renatures

A

below Tm

94
Q

the more GC pairs, the ___ melting point

A

higher

95
Q

the more GC pairs, the ___ melting point

A

lower

96
Q

structure which describes degree of supercoiling

A

tertiary

97
Q

level of structure which describescovalent modification of RNA

A

tertiary

98
Q

NA makes up how many percent of cell’s dry weight

A

5-15

99
Q

what type of organs are rich in NA

A

highly cellular

spleen liver thymus pancreas

100
Q

what type of organs are poor in NA

A

brain muscle tissues

101
Q

choice sample for DNA

A

tissues with cells with high nuc to cytoplasm volume ratio

102
Q

very good source of dna

A

lymphoid tissue

103
Q

best sourceof dna

A

thymus

104
Q

good substitute for source of dna

A

spleen

105
Q

types of interactions responsible for the rigid molecular configuration of NA

A

phosphodiester bonds
HB
VDW forces

106
Q

interactions involved in complementary base-pairing via HB inDNA and RNA

A

phosphodiester bonds

HB

107
Q

factors for choosing material for experiments

A

high content of DNA RNA
low DNase and RNase activity which are both hydrolases
NA from source are readily obtainable in essentially pure form

108
Q

HB bonding bet complementary base strans is stable between what pH

A

4 and 10

109
Q

N,C glycosidic bonds to purine bases are hydrolyzed at pH

A

3 OR LESS (APURINIC SITES)

110
Q

phosphodiester bonds and N,C glycosidic bonds are stable up to what temp

A

100C

111
Q

condition in which cell wall releases DNA when tissue is homogenized

A

lysis or disruption

112
Q

enzyme that causes most serious damage or degradation of DNA

A

DNAses or deoxyribonucleases

113
Q

enzymes that catalyze hydrolysis of 3’,5’ phosphodiester linkages

A

DNAses or deoxyribonucleases

114
Q

enzyme present on fingertips

causes spurious degradation of NA during purification

A

nucleases

115
Q

in the absence of required ___ and in the __, degradative enzyme becomes nonfunctional

A

ion and in the cold

116
Q

used to avoid degradation of dna

A

glass
rubber
plastic tools and ocntainers

117
Q

native dna is present in cell as what type of complex

A

DNA-protein complexes

118
Q

During the extraction process, proteins must be ____from DNA

A

dissoaciated or separated from DNA

119
Q

examples of mechanical stress that may cause cleavage shearing or scission of DNA chains

A

grinding, shaking, stirring, squiritng sol’n through narrown orifices

120
Q

does not cause damage to secondary structure of dna but reduces length of molecules

A

mechanical stress

121
Q

purified dna is best kept in solution or dry

A

in solution

122
Q

if precipitated DNA is kept dry, it tends to undergo

A

denaturation

123
Q

how to maintain dna in its secondary structure

A

keep it in 0.1 M acetate buffer

124
Q

what to do to inhibit growth of microorganism after purifying dna

A

add 0.001M sodium azide

storage temp must be 4C

125
Q

RNA of low MW is best kept dry or slurry

A

dry

126
Q

RNA of high MW is best kept dry or slurry

A

slurry under 75% aqueous alcohol

with 2% sodium azide at 4C

127
Q

scientific name of onion

A

Allium cepa

128
Q

steps in dna isolation

A

homogenization
dissociation and denaturation
purification of NA

129
Q

steps in dna isolation

disruption of cell membrane and membrane of subcellular particles to release nucleoprotein

A

homogenization

130
Q

steps in dna isolation
separates protein (deproteinization) and releases NA
NA is then precipitated out

A

dissociation and denaturation

131
Q

steps in dna isolation

based on principles of MW, size, structure, base composition etc

A

purification of NA

132
Q

homogenization involves what process to inactivate nucleses

A

denaturation

133
Q

onion sample is treated at what temp with a homogenizing solution

A

60C

134
Q

homogenizing solution
dilute saline solution
to precipitate nucleoproteins and separate it from other proteins

A

0.15M

135
Q

homogenizing solution
breaks ionic interaction between protein and NA and binds to the protein by hydrophobic interaction
makes it negatively charged

A

5% SDS

136
Q

homogenizing solution

binds Ca and Mg ions needed to activate nucleases and RNAse and which can form salts with anionic phosphate groups of NA

A

0.15M sodium citrate

137
Q

homogenizing solution

to dissolve proteins and bind Ca and Mg ions

A

0.001M EDTA

138
Q

WHY heat the onion sample at 60C

A

to dissolve NA separated from the protein without affecting HB in both NA and potein

139
Q

why cool in an ice bath

A

slow down activity of nucleases

140
Q

why treat with papain or meat tenderizer (dna)

A

denature all protein in aqueous medium

141
Q

what does denaturation do with the hydrophobic portion of proteins

A

expose them to be precipitated out

142
Q

why add ice cold 95% ethanol

A

to precipitate DNA and RNA

143
Q

after isolation describe dna

A

white fibrous or threadlike ppt which can be collected by spooling onto a glass rod

144
Q

scientific name of yeast

A

saccharomyces cerevisiae

145
Q

how much RNA does yeast contain

A

4% by weight

146
Q

in rna isolation, why heat with dilute alkali

A

separate from protein
extract rna and water soluble proteins
inactivate nucleases

147
Q

in rna isolation, why mix ethanol with conc HCl

A

to make alcohol more polar, thus precipitating the less polar NA, RNA

148
Q

buffer or solution used

A

tris-EDTA buffer of SSC solution

149
Q

meaning of TE and SSC

A

standard saline citrate

tris-EDTA

150
Q

why does dna and rna have sufficient absorptionin uv range

A

presence of aromatic nitrogen bases which contain conjugated double bonds

151
Q

major absorption band for purified dna and rna peaks at about

A

260nm

152
Q

primary contaminant in dna and rna

A

protein material with trp phe and tyr

153
Q

peak absorbance of protein material with trp phe and tyr

A

280 nm

154
Q

TYPICAL absorbance ratio for good quality NA

A

1.8-2

155
Q

absorbance ratio for isolated dna

A

1.8

156
Q

what does a small ratio indicate

A

increased contamination by protein

157
Q

what does a bigger ratio indicate

A

increased contamination by rna or denatured dna

158
Q

amt of NA and protein in sol’n can be determined using

A

monograph

159
Q

RNA has higher or lower absorption at 260 nm than DNA

A

higher

160
Q

why does RNA have higher absorption at 260 nm than DNA

A

because it is SS, nitrogen bases are exposed

161
Q

A ratio of highly purified RNA

A

1.85-2

162
Q

absorbance of RNA if ti has contaminants such as phenol, polysaccharides, peptides

A

230nm

162
Q

The symmetry of the sugar-phosphate backbone imparts a —- to the nucleic acid

A

Polarity

163
Q

The single-stranded nucleic acids may contain —– regions of —-

A

local regions of short complementary base pairing

164
Q

Since NA is single stranded, it has a strong tendency to adopt what conformation?

A

Random coil

165
Q

Location of RNA

A

Cytoplasm, rER, nucleolus

166
Q

Thermodynamically stable means lower or higher free energy?

A

Lower

167
Q

Intermolecular forces present in pi-pi complexation rxn

A

Van der Waals

Intermolecular interaction

168
Q

Why was hydrolysis performed

A

To separate the components of nucleic acids isolates

Botany (324 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions