KU BIOL 600 TEST 2 QUESTIONS AND CORRECT
ANSWERS
What is heme made of? - ANSWER porphyrin ring and Fe2+ (or Fe3+)
The function of this protein is to store oxygen in muscle cells - ANSWER
myoglobin
This type of binding is indicated by a sigmoidal-shaped binding curve. -
ANSWER cooperative
What is the oxidation state of iron in deoxyhemoglobin?
In oxyhemoglobin? - ANSWER Fe2+
Fe3+
How is heme bound to the polypeptide of hemoglobin? - ANSWER
proximal histidine forms a metal coordination bond with the iron of heme
Upon binding O2, what happens to the shape of the heme? - ANSWER
it flattens
How is O2 binding to one Hb subunit transmitted to the other Hb
subunits? - ANSWER 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? - ANSWER 2,3-BPG binds to,
and stabilizes the deoxy form of Hb
What residues in hemoglobin are involved in binding 2,3-BPG? -
ANSWER 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 _________. - ANSWER decrease
Bohr effect
Carbon dioxide will (increase/decrease) pH and (increase/decrease) O2-
binding affinity of Hb. - ANSWER decrease
decrease
This is the chemical form in which most of the carbon dioxide is
transported in the blood. - ANSWER 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 - ANSWER fetal hemoglobin
higher
What is the mutation in hemoglobin that leads to sickle-cell anemia? and
what happens to sickle-cell Hb? - ANSWER 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? - ANSWER myoglobin
Which protein is an O2 carrier (lungs to tissues)? - ANSWER
hemoglobin
These monosaccharides differ at a single asymmetric carbon -
ANSWER epimers
The storage form of glucose in animals - ANSWER glycogen
The storage form of glucose in plants - ANSWER starch
the enzymes that synthesize oligosaccharides - ANSWER
glycosyltransferases
ANSWERS
What is heme made of? - ANSWER porphyrin ring and Fe2+ (or Fe3+)
The function of this protein is to store oxygen in muscle cells - ANSWER
myoglobin
This type of binding is indicated by a sigmoidal-shaped binding curve. -
ANSWER cooperative
What is the oxidation state of iron in deoxyhemoglobin?
In oxyhemoglobin? - ANSWER Fe2+
Fe3+
How is heme bound to the polypeptide of hemoglobin? - ANSWER
proximal histidine forms a metal coordination bond with the iron of heme
Upon binding O2, what happens to the shape of the heme? - ANSWER
it flattens
How is O2 binding to one Hb subunit transmitted to the other Hb
subunits? - ANSWER 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? - ANSWER 2,3-BPG binds to,
and stabilizes the deoxy form of Hb
What residues in hemoglobin are involved in binding 2,3-BPG? -
ANSWER 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 _________. - ANSWER decrease
Bohr effect
Carbon dioxide will (increase/decrease) pH and (increase/decrease) O2-
binding affinity of Hb. - ANSWER decrease
decrease
This is the chemical form in which most of the carbon dioxide is
transported in the blood. - ANSWER 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 - ANSWER fetal hemoglobin
higher
What is the mutation in hemoglobin that leads to sickle-cell anemia? and
what happens to sickle-cell Hb? - ANSWER 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? - ANSWER myoglobin
Which protein is an O2 carrier (lungs to tissues)? - ANSWER
hemoglobin
These monosaccharides differ at a single asymmetric carbon -
ANSWER epimers
The storage form of glucose in animals - ANSWER glycogen
The storage form of glucose in plants - ANSWER starch
the enzymes that synthesize oligosaccharides - ANSWER
glycosyltransferases
