Questão 1
Responda
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red blood cell protein that transports oxygen via its four heme-bound subunits from the lungs to the tissues
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Gives blood its red color
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allosteric protein
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Quaternary structure
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Tertiary structure
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if abnormal in primary structure can lead to diseases or mutations such as sickle cell
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bind of oxygen is not cooperative
Questão 2
Responda
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binds oxygen in muscle cells
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displays cooperatively in oxygen binding and release
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is a quaternary structure
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can lead to sickle cell disease if abnormalities exist in primary structure
Questão 3
Questão
The ability of myoglobin and hemoglobin to bind oxygen depends on the presence of a heme group
Questão 4
Questão
The heme group consist of
Responda
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inorganic component called protoporphyrin and a central iron ion in the ferrous form, the only form that can bind oxygen
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organic component called protoporphyrin and a central iron ion in the ferrous form, the only form that can bind oxygen
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inorganic component called protoporphyrin and a central iron ion in the ferrous form, one out of many forms that can bind oxygen
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organic component called protoporphyrin and a central iron ion in the ferrous form, one out of many forms that can bind oxygen
Questão 5
Questão
The iron lies in the middle of the protoporphyrin bound to three nitrogens
Questão 6
Questão
Iron can from two additional bonds, at the [blank_start]fifth[blank_end] and [blank_start]sixth[blank_end] coordination sites
Responda
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fifth
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second
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fourth
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sixth
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third
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fifth
Questão 7
Questão
The imidazole ring of a histidine called the proximal histidine is occupied by the
Responda
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Fourth coordination
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Fifth coordination
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Sixth coordination
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Seventh coordination
Questão 8
Questão
The [blank_start]sixth[blank_end] coordination site binds [blank_start]oxygen[blank_end]
Questão 9
Questão
The structure of myoglobin prevents the release of reactive oxygen species
Questão 10
Questão
Superoxide is very reactive, and should it leave the heme, ferric iron (Fe3+) would result.
Questão 11
Responda
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does not bind oxygen
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does bind oxygen
Questão 12
Questão
Myoglobin with iron in the Fe3+ state is called
Responda
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metmyoglobin.
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metamyoglobin
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oxymyoglobin
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deoxymyoglobin
Questão 13
Questão
The distal histidine of myoglobin prevents the release of
Questão 14
Questão
A hydrogen bond donated by the distal histidine residue to the bound oxygen molecule helps stabilize oxymyoglobin
Questão 15
Questão
Myoglobin consist of
Responda
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a single polypeptide chain, formed of α- helices connected by turns, with one oxygen binding site
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a multiple polypeptide chains, formed of α- helices connected by turns, with one oxygen binding site
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a multiple polypeptide chains, formed of β- helices connected by turns, with one oxygen binding site
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a single polypeptide chain, formed of β- helices connected by turns, with one oxygen binding site
Questão 16
Questão
Hemoglobin consist of
Responda
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Four chains
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2 identical α chains
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4 identical α chains
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2 identical β chains.
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4 identical β chains.
Questão 17
Questão
Many of the helices in each subunit are arranged in a pattern also found in myoglobin, a structure called the [blank_start]globin[blank_end] fold
Questão 18
Questão
Hemoglobin binds oxygen cooperatively
Questão 19
Questão
[blank_start]Myoglobin[blank_end] displays a [blank_start]hyperbolic[blank_end] oxygen binding curve, while [blank_start]hemoglobin[blank_end] exhibits a [blank_start]sigmoid[blank_end] curve, indication that O2 binding and release is [blank_start]cooperative[blank_end]
Responda
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Myoglobin
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Hemoglobin
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hyperbolic
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sigmoid
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hemoglobin
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myoglobin
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sigmoid
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hyperbolic
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cooperative
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non-cooperative
Questão 20
Questão
Hemoglobin is not effective in providing oxygen to exercising tissue
Questão 21
Questão
Because of cooperatively between O2 binding sites,
Responda
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hemoglobin delivers more O2 to actively metabolizing tissues than would myoglobin or any noncooperative protein, even one with optimal O2 affinity
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hemoglobin delivers more O2 to actively metabolizing tissues than would myoglobin or any cooperative protein, even one with optimal O2 affinity
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myoglobin delivers more O2 to actively metabolizing tissues than would hemoglobin or any noncooperative protein, even one with optimal O2 affinity
Questão 22
Questão
The quaternary structure of deoxyhemoglobin is referred to as the [blank_start]T state[blank_end], while that of oxyhemoglobin is the [blank_start]R state[blank_end].
Responda
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T state
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R state
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R state
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T state
Questão 23
Questão 24
Questão 25
Questão
R state has a greater affinity for oxygen than does the T state
Questão 26
Questão
It is sequential in that in hemoglobin with one O2 bound,
Questão 27
Questão
It is concerted in that in hemoglobin with three O2 bound,
Questão 28
Questão
The transition from deoxyhemoglobin (T state) to oxyhemoglobin (R state) occurs upon oxygen binding.
Questão 29
Questão
2,3 Bisphosphoglycerate in red cells is crucial in determining the oxygen affinity of myoglobin
Questão 30
Questão
2, 3-Bisphosphoglycerate (2,3-BPG) stabilizes the [blank_start]T state[blank_end] of hemoglobin and thus facilitates the [blank_start]release[blank_end] of oxygen.
Responda
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T state
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R state
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release
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binding
Questão 31
Questão
2. 2, 3-BPG binds to a pocket in the hemoglobin tetramer that exists only when hemoglobin is in the R state.
Questão 32
Questão
In fetal hemoglobin,
Responda
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the β chain is replaced with a γ chain
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The fetal α2γ2 hemoglobin does not bind 2, 3-BPG as well as adult hemoglobin does.
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The reduced affinity for 2, 3-BPG results in fetal hemoglobin having a higher affinity for oxygen, binding oxygen when the mother’s hemoglobin is releasing oxygen
Questão 33
Questão
Carbon monoxide binds so tightly to iron of hemoglobin that it stabilizes the R state (binding of oxygen) to such a degree that the R to T transition does not occur.
Questão 34
Questão 35
Questão
Most carbon dioxide is carried to the lungs in the blood as bicarbonate ion.
Questão 36
Questão
Carbonic acid dissociates to form HCO3- and H+ resulting in a rise in pH inside the cell
Questão 37
Questão
Sickle cell anemia results from the aggregation of mutated deoxyhemoglobin molecules
Responda
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is a genetic disease caused by a mutation resulting in the substitution of valine for glutamate at position 6 of the β chains.
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can be fatal when both alleles of the β chain are mutated.
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trait offers some protection from malaria
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one allele is mutated and one is normal such individuals are asymptomatic.
Questão 38
Responda
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caused by an imbalanced production of hemoglobin chains
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another common genetic disorder of hemoglobin
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another common genetic disorder of myoglobin
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caused by the absence or underproduction of one of the hemoglobin chains
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caused by the presence or overproduction of one of the hemoglobin chains