quiz 3.2 NO and Nucleic acids Flashcards
1
Q
reason why NO can reach the targets before degradation
A
high diffu rate
low solubility in water
2
Q
NO was formerly called
A
endotelium-derived relaxing factor
3
Q
NO is produced via action of
A
nitric oxide synthase
4
Q
NO raeecting witth moclecular oxygens forms
A
N2O3
5
Q
NO reacting with superoxide forms
A
peroxynitrite
6
Q
the physiologic functions of NO are mediated through activation of soluble ______ to produce ______
A
guanylate cyclase
cGMP
7
Q
how does NO activate guanylate cyclase
A
NO binds the sixth ligand and breaks the heme-histidine bond
8
Q
what inactivates cGMP and stops the signal
A
phosphodiesterase 5
9
Q
the heme moiety of NO resembles
A
cytochrome p450
10
Q
2 functional domains of NO
A
oxygenase
reducatse
11
Q
the substrate binding site in the oxygenase domain is the site for
A
arginine
12
Q
parts of the oxygenase domain
A
heme moiety
substrate-binding site
tetrahydrobiopterin
tetra-coordinated zinc atom
13
Q
which part of the oxygenase domain is the binding site for electron transfer
A
tetrahydrobiopterin
14
Q
part of the oxygenase domain taht is for strucutural itnegrity
A
tetra-coordinated zinc atom
15
Q
the domain of NO that structurally resembles p450 reducatse
A
reductase domain
16
Q
connects the two domains and serves as the site for calmodulin attachment required for electron transfer from the reductase to te oxygenase domain
A
calmodulin-binding site
17
Q
the elctron donor in the enzymatic reaction of NOS
A
NADPH
18
Q
NADPH donated 2 electrons to ____ and reduces _____
A
FAD
FMN
19
Q
____ reduces heme iron to ferrous form to which oxygen can bind to
A
FMN
20
Q
source of nitrogen in NO
A
guanido group of arginine
21
Q
source of oxygen in NO
A
molecular oxygen
22
Q
synthesis of NO requires
A
2 O2
1.5 NADPH
23
Q
in the synth of NO, arignine is
A
oxidized to N-hydroxy-L-arginine
24
Q
in the 2nd step of NO, N-hydroxy-L-arginine is
A
oxidized to NO and citrulline
25
NO synth is inhibited by
CO
26
calmodulin-binding requires
influx of calcium to increase calcium conc.
27
______ binds to and activates NOS
calcium-calmodulin complex
28
when released ang potentially destructive reactiev oxygen species kapag NO synth
when no substrate but NOS is active
29
three major isoforms of NOS
neuronal
inducible
endothelial
30
the inducible isoform of NOS
iNOS/NOS 2
31
the membrane bound NOS isoform
eNOS/NOS 3
32
the indepedent NOS isoform
iNOS/NOS2
33
action of NOS 2
cytotoxicity
34
action of NOS 3
vasodilation
35
action of NOS 1
neurotransmission
36
NOS1 in skel msuces serves as
mediator of contractile force
37
nNOS is not normally induced at the transcirptional level therefore it is
constitively expressed
38
NO synth sis timulated by calcium influx through receptor-dependent channels following postsynaptic of ___________ receptors by _____-
N-methyl-D-aspartate
| glutamate
39
is NO removed via deactivation
no
40
how is NO terminated
interaction with their target
41
NO is produced by NOS1 in myenteric neurons of the _______
gastrointestinal
pulmonary
vascular
urogenital systems
42
NO in the PNS causes
smooth muscle relaxation
43
what happens when no nNOS in GI tract
pyloric stenosis
44
in the GI system, nNOS is involved in
gut motility and sphincter control
45
in the pulmo system, NO mediates
bronchodil
46
in the vacular system, NO is invovled in the neural control of the vascular system especially in the ________
control of cerebral blood flow
47
in the urogenital system, NO is involved in
urethra and bladder control and penile erection
48
NOS1 is associated with ___ in the skel system
alpha-syntrophin
49
NO2: is calmodulin bound at basal physiologic conditions?
yes
50
overstimulation of NOS2 may lead to
spetic shock
51
how is NOS3 antithrombotic and anit-inflamm
inhibits platelets and leukocytes
52
this NO isoform has unique terminals where myristoylation and palmitoylation occur
NOS3
53
inhibits NOS3
caveolin
54
if ________, NOS3 is not found in the caveolae so no NO synth
palmitoylation
55
involved in uotake of L-arginine to ensure a supply of substrate for NO synthesis
cationic amino acid transporter 1`
56
action of EDRF can be prevented by
superoxide
hgb + NO
analogues of arg
57
endothelial cells cannot produce EDRF without ____
arginine
58
explain the anti-atherosclerotic properties of NO
prevents adhesion to endothel
inhibit prolif and migration
dec. permeability of endothel
59
used for angina tx
nitroglycerin
60
potent inhib of PDE5
sildenafi;
61
side effect of sildenafil
cyanopsis
62
central dogma of molec biology
dna determines rna determines proteins
63
named that the transforming substance is DNA
Avery, McCarty, McLeod
64
father of modern genetics
francis galton
65
stated the transforming principle in pneumococcus/streptococcus (genetic role of DNA)
Frederick Griffith
66
identified parts of the DNA RNA
Lavene
67
identified the base pairings
Chargaff
68
identified the double helix
Watso, Crick, Wilkins
69
helped Watson, Crick and Wilkins in the study of the double helix with her xray diffraction
Franklin
70
showed that the DNA was the genetic material of the phage T2 by labeling DNA or proteins
Hershey and Chase
71
Hershey and Chase's experiment showed that
the protein does not infect, the DNA does
72
a nucleic acid has ____ ___ vdsnjghslfnva sbub
4 kinds of bases linked to a sugar-phosphate backbone
73
__ is the tranformation of DNA info into functional molecules
gene expression
74
most _______ genes are mosaics of introns and extrons
eukaryotic
75
a conjugated protein where the the prosthetic group is a class of organic compound known as nucleic acids
nucleotides
76
proesthetic group of nucleotides
nucleic acid
77
nonprotein group combined with a protein
prosthetic group
78
an example of nucleotides for carrying chemical energy
ATP
79
nucleotides are also components of enzyme cofactors such as
FAD
NAD
NADP
co A
80
an example of nucleotides serving as molecular mesengers
cAMP
81
an example of nucleotides serving as intermediate
SAM
82
the polymer strands of DNA are arranged in what manner
antiparallel
83
the Wtason-Crick model of DNA is in what form
B
84
the strandsa re held together and stabilized by
hydrogen bonds
| base-stacking interaction
85
which bonds have higher melting point
G-C pair
86
why higher melting temp ang G-C pair
coz more hydrogen bonds
87
nucleotides with phosphate removed
nucleoside
88
components of ribosomes playing a role in protein synth
rRNA
89
carry gngetic info from gene to the ribosome
mRNA
90
translate info in mRNA into an amino acid
tRNA
91
three components of nucleotides
nitrogenous base (purine or pyrimidine)
pentose (D-ribose or 2-deoxyribose)
phosphate group
92
Pyrimidines in DNA and RNA
Uracil
Cytosine
thymine
93
Each phrimidine is linked to the sugar through the ___ position
n1
94
Common purine
Adenine guanine
95
Purines are attached to sugar at ___ position
N9
96
Nucleoside is a nitrogenous base covanlently bound in an ________
N-beta-glycosidic linkage to the 1'-carbon of a pentose sugar
97
A nu leotide is a nucleoside with at least one phosphate group attached to
5' carbon of the sugar
98
Nucleotides are linked through their ____ in _____ linkages between the _____ and _____ of the next one
phosphate groups
Phosphodiester
5' hydroxyl of one pentose to the 3' hyxdroxyl of the next
99
Strands of nucleic acid containinh <50 nucleotides are called
Oligonucleotides
100
Stands with >50 nucleotides are called
Polynucleotides
101
Nucleobase glycosylated with either pentose sugar is called
Nucleoside
102
Ribonuclosides seen in RNA
A
G
C
U
103
Doexyribonucleosides found in DNA
dA
dG
dC
dT
104
Aling nitrogenous base ung 6 sided
Pyrimidine
105
Aling nitrogenous bases ung 9 sided
Purine
106
Adenine is aka
6-aminopurine
107
cytosine is aka
2-oxy-4 aminopyrimidine
108
Uracil is aka
2,4-dioxypyrimidine
109
Eukaryotic cells contain DNA combined with what protein
Histone
110
Beadlike structures with MW of 10k-20k
Histones
111
Classes of histones
```
Histone 1
H2A
2B
3
4
```
112
How are histones classified
Accdg to arg and lys content
113
Which histone bidns to the outside of the DNA
H1
114
each histone cluster is conposed of
2 moclecules each of 2B 2A 3 4
115
Ilang turns kpag nagwrap around ung DNA sa histone cluster
2
116
2 classes of nu leic acid
DNA RNA
117
histone with highest lys content
H1
118
Histone with highest arg conc
H4
119
Bases can exist in what orientations about the N-glycosidic bond
Syn
| Anti
120
two isomer forms of purines and pyrimidines
lactam-lactim
| keto enol
121
for those with amino groups, tautomers formed may be ______
amine-imine
122
phosphorylation of nucleotides will inc or dec solubility?
increase
123
nucleoside or base: which is more soluble?
nucleoside
124
which is resistant to acid treatment
pyrimidines
125
charge of nucleosides at biological pH
neutral
126
which are stable over a wide range of pHs
nucleotide and side
127
under strongly basic conditions, what happens to the nucleic acid
hydrolysis of phosphate esters
128
in which condtion is the N-glycosidic bonds more labile
acidic
129
when ang protonation of purine, kpag
high temp
130
maximum absoprtion of light by nuecleic acids occurs at
260nm
131
the absorbance property of nucleic acids is due to its
nitrogenous bases
132
purine or pyrimidine: which has higher abrsobranc
purine
133
what ha[[ens to absorbance when nucleic acid is hydrolyzed with free bases (?)
hyperchromicity
134
synthesis of strands go in what direction
5' - 3-'
135
how do you write/read the the nucleotide sequence
5' - 3'
136
the bases in the interior of the helix are aligned at nearly
90deg relative to the axis
137
A-T or G-C: which has more hydrogen bonds
G-C 3 H bonds
A-T 2 H bonds
A-T easier to destroy
138
helices rich in ____ can exist as left-handed conformation in Z-DNA
G-C dinucleotides
139
Watson and Crick's DNA model is in what conformation
B
140
this is a prat of a strand caused by asymmetry
grooves
141
the longer groove
major
142
the major groove in the B-form is
wide and deep
143
deanturation of the DNA causes what effects
hyperchromic effect and inc. UV absorption
144
when the 2 strands are separated, the indiv strands assume what conformation
random coil
145
factors determining stability and Tm of DNA
nature of solvent
pH
conc of ions
146
point where 50% of the DNA exists as single strands
Tm
147
process where the melted DNA is cooled and reforms its base pairs again
annealing or hybridization
148
common affinity matrixx for HPLC of DNA
hydroxyapatite
149
material of chpoice for electrophoresis
agarose
150
in eelctrophoresis, the DNA will migrate to which electrode
anode
151
features of tRNA
```
cloverleaf like
5' terminal PO4
3' terminal OH
dihydrouridine in D arm
anticodon arm
pseudouridine
variable arm
```
152
the T arm or TyC arm in the tRNA contains
pseudouridine
153
the 3' terminal OH group of the tRNA is found in where
amino acid arm
154
the bases found in the 3' end
CCA
155
amino acids are attracted to and activated when attached ro
3' end
156
posttranscriptional events
capping
polyadeny.lic tail
splicing
157
seen in the 5' end of mRNAs
7-methyl guanylic acid
158
gthe 7-methyl guanylic acid in the 5' end of mRNA is attached via
5'-5' triphosphate linkage
159
common rRNA in eukaryotes
80s
160
common rRNA in prokaryote
70s
161
rRNA is ___ and _____
35% protein
| 65% RNA
162
snRNA form small complexes called
small nuclear ribonucleoproteins
163
process where the noncoding parts are taken out of the DNA
splicing
164
the template strand
3'5'
165
the nontemplate/coding strand
5'3'
166
postranscriptional capping is for
better recognition of whatever blabla
167
the poattranscriptional polyadenylate tail is for
stability
