KU BIOL 600 TEST 2 EXAM 2025
QUESTIONS AND ANSWERS
What is heme made of? - ANS porphyrin ring and Fe2+ (or Fe3+)
The function of this protein is to store oxygen in muscle cells - ANS myoglobin
This type of binding is indicated by a sigmoidal-shaped binding curve. - ANS cooperative
What is the oxidation state of iron in deoxyhemoglobin?
In oxyhemoglobin? - ANS Fe2+
Fe3+
How is heme bound to the polypeptide of hemoglobin? - ANS proximal histidine forms a
metal coordination bond with the iron of heme
Upon binding O2, what happens to the shape of the heme? - ANS it flattens
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.
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
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, 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
Lower pH will (increase/decrease) the oxygen-binding of hemoglobin. This is known as the
_________. - ANS decrease
Bohr effect
Carbon dioxide will (increase/decrease) pH and (increase/decrease) O2-binding affinity of Hb. -
ANS decrease
decrease
This is the chemical form in which most of the carbon dioxide is transported in the blood. -
ANS bicarbonate
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
What is the mutation in hemoglobin that leads to sickle-cell anemia? and what happens to
sickle-cell Hb? - ANS glutamate in normal hemoglobin is mutated to a valine residue in sickle-
cell anemia this mutation makes Hb more hydrophobic, making Hb molecules stick together,
forming fibrils, which deform the shape of red blood cells
Which protein is an oxygen storage in tissues? - ANS myoglobin
Which protein is an O2 carrier (lungs to tissues)? - ANS hemoglobin
These monosaccharides differ at a single asymmetric carbon - ANS epimers
2 Copyright ©2025 THESTAR ALL RIGHTS RESERVED
QUESTIONS AND ANSWERS
What is heme made of? - ANS porphyrin ring and Fe2+ (or Fe3+)
The function of this protein is to store oxygen in muscle cells - ANS myoglobin
This type of binding is indicated by a sigmoidal-shaped binding curve. - ANS cooperative
What is the oxidation state of iron in deoxyhemoglobin?
In oxyhemoglobin? - ANS Fe2+
Fe3+
How is heme bound to the polypeptide of hemoglobin? - ANS proximal histidine forms a
metal coordination bond with the iron of heme
Upon binding O2, what happens to the shape of the heme? - ANS it flattens
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.
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
1 Copyright ©2025 THESTAR ALL RIGHTS RESERVED
, 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
Lower pH will (increase/decrease) the oxygen-binding of hemoglobin. This is known as the
_________. - ANS decrease
Bohr effect
Carbon dioxide will (increase/decrease) pH and (increase/decrease) O2-binding affinity of Hb. -
ANS decrease
decrease
This is the chemical form in which most of the carbon dioxide is transported in the blood. -
ANS bicarbonate
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
What is the mutation in hemoglobin that leads to sickle-cell anemia? and what happens to
sickle-cell Hb? - ANS glutamate in normal hemoglobin is mutated to a valine residue in sickle-
cell anemia this mutation makes Hb more hydrophobic, making Hb molecules stick together,
forming fibrils, which deform the shape of red blood cells
Which protein is an oxygen storage in tissues? - ANS myoglobin
Which protein is an O2 carrier (lungs to tissues)? - ANS hemoglobin
These monosaccharides differ at a single asymmetric carbon - ANS epimers
2 Copyright ©2025 THESTAR ALL RIGHTS RESERVED
