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KU Biol 600 Test 2 Questions with Detailed
Verified Answers
Question: What is heme made of?
Ans✅ ✅: porphyrin ring and Fe2+ (or Fe3+)
Question: The function of this protein is to store oxygen in muscle cells
Ans✅ ✅: myoglobin
Question: This type of binding is indicated by a sigmoidal-shaped
binding curve.
Ans✅ ✅: cooperative
Question: What is the oxidation state of iron in deoxyhemoglobin?
In oxyhemoglobin?
Ans✅ ✅: Fe2+
Fe3+
Question: How is heme bound to the polypeptide of hemoglobin?
Ans✅ ✅: proximal histidine forms a metal coordination bond with the iron of heme
Question: Upon binding O2, what happens to the shape of the heme?
Ans✅ ✅: it flattens
Question: How is O2 binding to one Hb subunit transmitted to the other
Hb subunits?
Ans✅ ✅: Upon O2-binding, the shape of the heme flattens, which shifts the position
of the proximal histidine. This effect is transmitted to the alpha-helix where the
proximal histidine is, and eventually to the other Hb subunits.
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Question: Why does the binding of 2,3-bisphosphogycerate to
hemoglobin (increase,decrease) its affinity to oxygen?
Ans✅ ✅: 2,3-BPG binds to, and stabilizes the deoxy form of Hb
Question: What residues in hemoglobin are involved in binding 2,3-
BPG?
Ans✅ ✅: 2,3-BPG is negatively charged; it binds to His and Lys residues, which are
positively charged
Question: Lower pH will (increase/decrease) the oxygen-binding of
hemoglobin. This is known as the _________.
Ans✅ ✅: decrease
Bohr effect
Question: Carbon dioxide will (increase/decrease) pH and
(increase/decrease) O2-binding affinity of Hb.
Ans✅ ✅: decrease
decrease
Question: This is the chemical form in which most of the carbon dioxide
is transported in the blood.
Ans✅ ✅: bicarbonate
Question: This hemoglobin is composed of two α chains and two γ
chains. This hemoglobin has (lower/higher) affinity for oxygen compared
to hemoglobin made of a and b chains
Ans✅ ✅: fetal hemoglobin
higher
Question: What is the mutation in hemoglobin that leads to sickle-cell
anemia? and what happens to sickle-cell Hb?
KU Biol 600 Test 2 Questions with Detailed
Verified Answers
Question: What is heme made of?
Ans✅ ✅: porphyrin ring and Fe2+ (or Fe3+)
Question: The function of this protein is to store oxygen in muscle cells
Ans✅ ✅: myoglobin
Question: This type of binding is indicated by a sigmoidal-shaped
binding curve.
Ans✅ ✅: cooperative
Question: What is the oxidation state of iron in deoxyhemoglobin?
In oxyhemoglobin?
Ans✅ ✅: Fe2+
Fe3+
Question: How is heme bound to the polypeptide of hemoglobin?
Ans✅ ✅: proximal histidine forms a metal coordination bond with the iron of heme
Question: Upon binding O2, what happens to the shape of the heme?
Ans✅ ✅: it flattens
Question: How is O2 binding to one Hb subunit transmitted to the other
Hb subunits?
Ans✅ ✅: Upon O2-binding, the shape of the heme flattens, which shifts the position
of the proximal histidine. This effect is transmitted to the alpha-helix where the
proximal histidine is, and eventually to the other Hb subunits.
, Page | 2
Question: Why does the binding of 2,3-bisphosphogycerate to
hemoglobin (increase,decrease) its affinity to oxygen?
Ans✅ ✅: 2,3-BPG binds to, and stabilizes the deoxy form of Hb
Question: What residues in hemoglobin are involved in binding 2,3-
BPG?
Ans✅ ✅: 2,3-BPG is negatively charged; it binds to His and Lys residues, which are
positively charged
Question: Lower pH will (increase/decrease) the oxygen-binding of
hemoglobin. This is known as the _________.
Ans✅ ✅: decrease
Bohr effect
Question: Carbon dioxide will (increase/decrease) pH and
(increase/decrease) O2-binding affinity of Hb.
Ans✅ ✅: decrease
decrease
Question: This is the chemical form in which most of the carbon dioxide
is transported in the blood.
Ans✅ ✅: bicarbonate
Question: This hemoglobin is composed of two α chains and two γ
chains. This hemoglobin has (lower/higher) affinity for oxygen compared
to hemoglobin made of a and b chains
Ans✅ ✅: fetal hemoglobin
higher
Question: What is the mutation in hemoglobin that leads to sickle-cell
anemia? and what happens to sickle-cell Hb?
