Question 1
Answer
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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
Question 2
Answer
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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
Question 3
Question
The ability of myoglobin and hemoglobin to bind oxygen depends on the presence of a heme group
Question 4
Question
The heme group consist of
Answer
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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
Question 5
Question
The iron lies in the middle of the protoporphyrin bound to three nitrogens
Question 6
Question
Iron can from two additional bonds, at the [blank_start]fifth[blank_end] and [blank_start]sixth[blank_end] coordination sites
Answer
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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
Question 7
Question
The imidazole ring of a histidine called the proximal histidine is occupied by the
Answer
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Fourth coordination
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Fifth coordination
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Sixth coordination
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Seventh coordination
Question 8
Question
The [blank_start]sixth[blank_end] coordination site binds [blank_start]oxygen[blank_end]
Question 9
Question
The structure of myoglobin prevents the release of reactive oxygen species
Question 10
Question
Superoxide is very reactive, and should it leave the heme, ferric iron (Fe3+) would result.
Question 11
Answer
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does not bind oxygen
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does bind oxygen
Question 12
Question
Myoglobin with iron in the Fe3+ state is called
Answer
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metmyoglobin.
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metamyoglobin
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oxymyoglobin
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deoxymyoglobin
Question 13
Question
The distal histidine of myoglobin prevents the release of
Question 14
Question
A hydrogen bond donated by the distal histidine residue to the bound oxygen molecule helps stabilize oxymyoglobin
Question 15
Question
Myoglobin consist of
Answer
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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
Question 16
Question
Hemoglobin consist of
Answer
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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.
Question 17
Question
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
Question 18
Question
Hemoglobin binds oxygen cooperatively
Question 19
Question
[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]
Answer
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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
Question 20
Question
Hemoglobin is not effective in providing oxygen to exercising tissue
Question 21
Question
Because of cooperatively between O2 binding sites,
Answer
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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
Question 22
Question
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].
Answer
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T state
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R state
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R state
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T state
Question 23
Question 24
Question 25
Question
R state has a greater affinity for oxygen than does the T state
Question 26
Question
It is sequential in that in hemoglobin with one O2 bound,
Question 27
Question
It is concerted in that in hemoglobin with three O2 bound,
Question 28
Question
The transition from deoxyhemoglobin (T state) to oxyhemoglobin (R state) occurs upon oxygen binding.
Question 29
Question
2,3 Bisphosphoglycerate in red cells is crucial in determining the oxygen affinity of myoglobin
Question 30
Question
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.
Answer
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T state
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R state
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release
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binding
Question 31
Question
2. 2, 3-BPG binds to a pocket in the hemoglobin tetramer that exists only when hemoglobin is in the R state.
Question 32
Question
In fetal hemoglobin,
Answer
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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
Question 33
Question
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.
Question 34
Question 35
Question
Most carbon dioxide is carried to the lungs in the blood as bicarbonate ion.
Question 36
Question
Carbonic acid dissociates to form HCO3- and H+ resulting in a rise in pH inside the cell
Question 37
Question
Sickle cell anemia results from the aggregation of mutated deoxyhemoglobin molecules
Answer
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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.
Question 38
Answer
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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