quiz 2.1 O2 and CO2 Flashcards
1
Q
exchange of gases between external and internal environment
A
ventilation
2
Q
exchange of gas between tissue and blood
A
internal respi
3
Q
how does blood and tissue exchange gases
A
diffusion
4
Q
conserved amino acid in both hb and mb
A
his F8 and E7
phe CD1 and leu F4
gly B6
5
Q
these amino acids in hb and mb are for heme contact (hydrophobic poket)
A
phe CD1 and leu F4
6
Q
this amino acid in hb and mb allows the close approach of helices B and E
A
gly B6
7
Q
compact globular protein with ____ amino acids folded in ____ right handed alpha helices A to H
A
myoglobin
153
9
8
Q
approximately 75% of Hb is in the form of an
A
alpha helix
9
Q
Hb has __ heme groups and therefore ___ oxygen binding sites
A
4
4
10
Q
characteristics of Hb
A
64 kd
heterotetramer with 2 pairs of globin polypeptde chains
11
Q
structure of HbA
A
alpha2/beta2
12
Q
structure of Hb Gower1
A
zeta2/epsilon2
13
Q
structure of Hb Portland
A
zeta2/gamma2
14
Q
the prosthetic group of Hb and Mb located in the hydrophobic pocket
A
heme
15
Q
structure of heme
A
protoporphyrin ring with bound iron
16
Q
organic portion of heme
A
protoprphyrin ring
17
Q
structure of protoporphyrin ring
A
4 pyrroles linked by methenyl bridges
18
Q
groups/substituents seen in the structure of heme
A
propionate
vinyl
pyrrole
19
Q
sharp bands seen when heme absorbs visible lights and read at 400nm absorpotin
A
Soret band
20
Q
ano absorption binabasa heme
A
400nm
21
Q
substituents attached to pyrolle
A
methyl
vinyl
propionate
22
Q
iron in heme bind to how many ligands
A
6
23
Q
ano ung 6 na ligands bound to iron ng heme
A
4 of 6 to N of pyrroles
5th to his F8
6th for oxygen
24
Q
bond linkinf the first and second oxygen lies at what angle
A
121 degrees
25
the state aka deoxy conformation
Tense state
26
the state aka oxy conformation
Relaxed state
27
deoxyHb is stabilized in a constrained or tense configuration by
inter and intrasubunit salt bonds
28
oxygen binds to and pulls the iron toward where
the heme plane
resulting in the straightening of the dome shaped heme
29
angle of rotation of alpha2/beta2 during oxygenation
15 degrees
30
what is broken in the heme during oxygenation
8 salt bridges taht stabilize the T state
31
what is decreased in heme during oxygenation
size of central cavity
32
what is created during oxygention of heme
new hydrogen bonds in alpha1/bet2 interface
33
the iron in unoxygented Hb and Mb lies ____ outside the plane of the heme ring
.03 nm
34
puckering of the heme is directed where
towards proximal his F8
35
when oxygenated, the iron moves to within ___ of the heme plane
.01 nm
36
during deoxygenation, the beta chains rotate apart by approximately
.7 nm
37
the pasok of the heme into the plane during oxygenation si caused by what
stearic repulsion
38
the second oxygen is oriented _____ the distal his E7
away
39
partial pressure required for 50% saturation
P50
40
curve for myoglobin shows what shape
hyperbolic
41
P50 for myoglobin
2 mm
42
which has higher affinity, Mb or Hb
Mb @ 2mm P50
43
curve for hemoglobin shows what shape
sigmoidal
44
interaction where binding of O2 facilitates binding of additional O2 to other heme group
cooperativity
45
P50 for hemoglobin
26 torr
46
why sigmoidal ung hemoglobin
difficult binding of 1sy oxy
easy 2nd and 3rd
difficult for 4th
47
this provides info on the dgree of cooperativity
Hill coefficient
48
nH = 1 shows
no cooperativity
49
nH > 1.0 shows
positive coop
50
nH < 1.0 shows
neg coop
51
nH of Mb
1.0
52
nH of Hb
2.8
53
refers to the fold change in pO2 required to change Y =0.1 to 0.9 (10% saturation to 90%)
cooperativity index Rx
54
cooperativity index is computed from
nH
55
Mb Rx
81
56
Hb Rx
4.8
57
causes shift to the right
increase in temp, H protons, 2,3 BPG, altitude
58
binding of O2 to the T state causes concerted conformational change
Monod Wyman Changuex
59
allows a serial transformation of the subunits where there exist intermediate transformations between T to R states
Koshland Nemethy Filmer
60
the glycosylation of Hb requires the ___ type of rearrangement
Amadori
61
level of HbA1c reflect the mean blood glucose over ____ weeks because halflife of RBCs is 60days
6-8wks
62
inherited anomalies of Hb synthesis resulting from mutation in the globin genes
hemoglobinopathies
63
cause of Hb S
glu6 to val
64
the replacing valine in position 6 produces ___ on teh exterior of the molecule
sticky patch
65
Hb S causes what shift
rightward
66
P50 in Hb S
31
67
which does not contain the sticky patch in transfused blood
deoxy Hb
68
oxygenation has what effect on Hb S
masking of complimentary site thus prevention of sickling
69
characterized by reduced of one or more globin synthesis
thalassemia
70
characteristic products of alpha thalassemia trait
Hb Bart
71
ilang deletion sa alpha thalassemia-2
one
72
ilang deletion sa alpha thalassemia trait
2
73
ilan deletion sa Hgb H
3
74
absence of alpha chains what dse
Hydrops fetalis
75
total absence of beta chains what dse
thalassemia major
76
major end product of aerobic metab
CO2
77
normal aerobic conditions generate more than _____ of CO2 per day
13mol (.5 to 1kg)
78
process in transportation of CO2 from tissue to lungs thru circulation
convection
79
CO2 is _________ than O2
20x more soluble
80
formed from the rxn of CO2 and H20 catalyzed by the enzyme carbonic anhydrase
HCO3- bicarbonate
81
enzyme that catalyzes formation of HCO3-
carbonic anhydrase
82
percentages of CO2 in body
10% as dissolved
20% with proteins
70% bicarbonate
83
formed from the rxn of CO2 with the amino groups of proteins (like Hgb) within erythrocytes
carbaminohemoglobin
84
CO2 combines with the what of proteins
terminal NH2 (uncharged, aliphatic)
85
____________ forms carbamino mmroe readily thatn ________
deoxy Hb; oxy Hb
86
pH within RBC in carbamino form is
approx. 7.2
87
major acid produced by the body and acts as its own buffer
carbonic acid
88
makes hemoglobin an important buffer
isohydric exchange
89
describes how oxygen conc determines affinity for CO2
Haldane effect
90
hgih pCO2 unloads O2
Bohr effect
91
low pCO2 loads O2
reverse Bohr
92
high pO2 unloads CO2
Haldane
93
low pO2 loads CO2
reverse Haldane
94
oxygen shifts the CO2 curve to
right
95
CO2 curve when PaO2 is @ 95 mmHg
lower curve (down, right)
96
CO2 curve when PvO2 is @ 40 mmHg
upper curve (up, left)
97
in CO2 dissoc curve, CO2 content in tissues move from point ___ to ____
A to V
98
in CO2 dissoc curve, CO2 content in lungs move from point ___ to ___
V to A
99
chloride shift aka
hamburger effect
100
function of chloride shift
maintains electrical neutralit/balance
101
chloride shift is caused by exchange of what
bicarbonate forCL-
102
chloride ions enter RBC to establish elec neutrality. what effect
Donnan effect
103
chloride shift movement in tissues
influx of chloride
104
chloride shift movement in lungs
efflux of chloride
105
molecule that has a single unpaired electron in an orbital; highly reactive
radicals
106
action of radicals
initiate chain rxns by stealing an electron from neighboring molecules
107
free radicals are generated by
homolytic cleavage of covalent bonds
loss of a singl electron
addition of an electron
108
biradical atom
oxygen
109
how are the spins of the two solo electron of oxygen
parallel
110
difficult flipping of an oxygen electron
spin restriction
111
O2 is capable of accepting how many electrons
4
112
once O2 accepts one electron, it becomes
superoxide
113
theory states that an electron cannot readily oxidize a covalent bond because the other electron needs to flip its spin
antibonding
114
major oxygen metabolites produced by one-electron reduction of oxygen
ROS
115
superoxide
H2O2
hydroxyl free
which is not a radical
H2O2
116
eto ung tuloy tuloy na pagbuo ng radicals kapag steal nang steal ung dating radicals
cytotoxic oxidative chain rxn
117
formed from free O2 by donating an elecctron to another free radical
sueproxide
118
why can't superoxide diffuse far from site of origin
limited lipid solubility
119
superoxide is produced where or when
ETC
120
generation of hydroxyl free rads by rxn with a transition metal
fenton rxn
121
rxn of superoxide with H202 to form other ROSs
Haber Weiss rxn
122
precursor of the powerful oxidzing agent HOCl
H202
123
powerful ozidizing agent from H2O2
HOCl
124
rxn when forming H2O2 from O2
dismutation rxn
125
most toxic ROS
hydroxyl radicals
126
rxns involved in producing hydroxyl radicals
Fenton nd Haber Weiss
127
hydroxyl radicals are very damaging because of this intermediate effect
initiation of lipid peroxidation
128
cis or trans ano mas common na maging radical
cis
wtf question
129
HOCl is produced in neutrophils during what
respiratory burst
130
toxicity of HOCl is thru
halogenation and oxidation
131
how is HOCl formed
myeloperoxidase on CL ions in the presence of H2O2
132
produced at high oxygen tension from absorption of UV light
O2 singlet oxygen
133
sppin ng singlet oxygen
anti-parallel
134
NO is produced by
nitric oxide sythase
135
NO is synthesized from
argining
136
anong type ung NO
type 2 inducible
137
a strong oxidizing agent but not a free radical
ONOO peroxynitrite
138
peroxynitrie is formed from
superoxide + nitric oxide
139
kinds of sources of ROS
accidental
physiologic
deliberate
exogenous
140
coenzyme Q is what kind of source ng rOS
accidental
141
what ROS is formed in ETC or is an accidental byproduct
superoxide
142
respiratory burst is what kind of source of ROS
deliberate
143
process in which cells consume large amounts of oxygen during phagocytosis and release ROS
respiratory burst
144
how is ROS formed in NADPH oxidase
transfer of electron from NADPH to O2
145
hydrogen peroxide is formed by what
superoxide dismutase
146
the formation of HOCl from H2O2 is catalyzed by
myeloperoxidase
147
oxidatively degrades the neurotransmitter dopamine and geenrate H2O2 at the mitochondrial membrane of certain neurons
monoamine oxidase
148
generates H2O2 rather than FAD(2H) durind the oxidation of very long fatty acid chains
peroxisomal fatty acid oxidase
149
an enzyme of purine degradation that can reduce O2 to superoxide or H2O2 in the cytosol
xanthine oxidase
150
believed to be a major contributor to ischemia-reperfusion injury
xanthine oxidas
151
xanthine oxidase is believed to be a major contribution to
ischemia-reperfusion injury
152
formed as intermediates in the pathways for synthesis of many eicosanoids including leukotrienes and prostaglandins
lipid peroxides
153
xeogenous sources of ROS
```
ionizing radiation
tobacco
drugs
alcohol
inorganic particles
gases
```
154
this drug has pro-oxidant activity
methotrexate
155
iron deposition in smokers' lungs can cause what rxn
Fenton
156
an antibiotic that may be a source of ROS
nitrofurantoin
157
chlorine radicals from CFCs are formed thru
photodissociation
158
steps in membrane attack by lipid peroxy radicals
lipid peroxidation
propragation
degradation
termination
159
in lipid eproxidation, where does free radicals extract hydrogena tom from
polyunsaturated lipids
160
lipid radical reacts with O2 and forms what
lipid peroxy radical and lipid peroxide
161
used as an indicator of fre radical damage in the body
malondialdehyde
162
termination of the formation of lipid peroxy radicals are caused by
vit E and other lipid-soluble antioxidants
163
what are the amino acids susceptible to hydroxyl radical attack and oxdiative damage
```
proline
histidine
arginine
cysteine
methionine
```
164
main cellular defenses against oxygen toxicity
cellular leve
antioxidant scavenging
nonenzymatic defense
165
cellular level defense against oxygen toxicity
compartmentalization
metal sequestration
repair mechanism
166
disabling iron to participate in Fenton rxn
iron sequestration
167
what are the antioxidant scavenging enzymes
SOD
catalse
glutathione reductase
glutathione peroxidase
168
this is the primary defense against oxidative stress because superoxide is a strong initiator of chain rxns
SOD
169
three isoenzyme forms of SOD
cooper-zinc in cytosol
manganese in mitochondria
copper-zinc in extracellular
170
heme-containing enzyme catalyzing dismutation of H2O2 into water and oxygen
catalase
171
highest catalase activity can be seen in
kidney and liver
172
catalse is found principally where
peroxisome
173
which is better? catalase or glutathione peroxidase? and why
gluta bcoz no oxygen formed from H2O2
174
amino acids in glutathione
glucine
cysteine
glutamic
175
catalyzes the reduction of hydrogen peroxide and lipid peroxides by glutathione
glut peroxidase
176
complete name of glutathione
gamma-glutamylcysteineylglycine
177
the reactive _______ in glutathione peroxidase reduce H2O2 to water and lipid peroxides to non-toxic alcohols
sulfhydryl groups
178
what happens to sulfhydryl groups during action of glutathione peroxidase
oxidized to disulfide
179
glutathione peroxidase is found primarily in
cytosol and mitochondria
180
reduces oxidized glutathione (GSSG) back to the reduced form
glutathione reductase
181
major source of glutathione reductase
PPP/HMP
182
glutathione reductase contains ______ and catalyzes transfer of electrons from NADPH to the disulfide bond of GSSG
FAD
183
a common structure in non-enzymatic antioxidants
conjugated double bond system that may be an aromatic ring
184
most widely distributed antioxidant in nature
vit E (tocopherol)
185
among toxxopherols, this is the most potent
alpha tocopherol
186
fully oxidized form of tocopherol
tocopheryl quinine
187
tocopheryl radical is stabilized by the fully substituted benzoquinone ring and does not propagate the radical rxn, there it is an effective __________
radical trap
188
hydrophilic vitamin and best functions in aqueous environment
vit C
189
these indirectly scavenges oxygenf ree radicals b recycling tocopherol to the reduced form
chain breaking antioxidant
190
term applied to the beta carotene
carotenoids
191
prcursor of vit A
beta carotene
192
eaxmple of chain breaking antioxidants
vit C
| carotenoids
193
action of carotenoids as antioxidant
reacts with lipi peroxidation products to terminate rxn
194
what scavenges singlet oxygens
carotenoids
195
a toxic effect of beta carotene
yellowing of skin @ >20mg/day
196
group of strucutrally similar compounds containing two spatially separate aromatic rings
flavonoids
197
sample sources of lavonoids
red win
green tea
chocolate
198
action of flavonoids
inhibits xanthine oxidase
chelate Fe and Cu
doantes electrons to superoxide or lipid peroxy radicals
maintenance of vit E
199
endogenous antioxidants
uric acid
| melatonin
200
uric acid accounts for the major ____________________ of plasma
free radical trapping capacity
201
secretory product of pineal gland
melatonin
202
functions in the circadian rhythm, light dark signal transduction and sleep induction
melatonin
203
effectiveness of melatonin as antioxidant is due to its
lack of pro-oxidant activity
| joint hydrophilic phobic nature
204
action of metal chelators as antioxidants
bind iron and copper
205
example of metal chelators
ferritin
transferrin
cerulopasmin
albumin
206
transferrin binds
iron
207
multi subunit protein shell surrounding iron core
ferritin
208
convert Fe2 to 3
ceruloplasmin
209
binds copper tightly and iron weakly
albumin
