Bb450, exam 2 questions well answered
graded A+
Units and labels of the oxygen binding curve to portray myoglobin and
hemoglobin. Differences - correct answer ✔✔x is partial pressure O2 (pO2)
y fractional saturation (% saturation)
myoglobin, low p50, hyperbolic
hemoglobin, high p50, sigmoidal
If a hemoglobin is in the T state, how does its affinity for oxygen compare to that
of
hemoglobin in the R state? - correct answer ✔✔T has a lower affinity than the R
state hb
How does 2,3 BPG increase the ability of hemoglobin to release oxygen to the
tissues? - correct answer ✔✔By binding to the central cavity and preventing the
02-induced conformational changes, 2,3-BPG causes the T-state to be favored
state. Hb is therefore better able to release O2.
Explain how a) acidification of the blood and b) increasing carbon dioxide in the
blood
each change the affinity of hemoglobin for oxygen. - correct answer ✔✔Lowering
the pH and increasing the CO2 concentration favor the T-state, lowering the
affinity of Hb for 02. Protonation of Hb (lowering the pH) and carbamylation of Hb
, increasing the CO2 concentration promote the formation of T-state stabilization
ionic interactions
How does the fetus win out in the competition for the mother's oxygen? Next
question: A
smoker is pregnant and carrying a fetus. Assuming the 2,3 BPG could cross into
the fetal blood,
what effect would it have on the fetus? - correct answer ✔✔Fetal Hb
(alpha2,gamma2) is an R-state and does not bind in comparison to adult
Hb(alpha2,beta2)(T-state) and so a smoker or someone with asthma has increase
amount of 2,3 BPG and so the fetus will get the most oxygen. If the 2,3 BPG was in
the fetus bloodstream it wouldn't matter because it wouldn't bind.
What is the molecular basis of sickle cell anemia? - correct answer ✔✔A single
amino acid substitution (Valine instead of Aspartic Acid in position 6 of the beta
chains) causes neighboring hb molecules to become sticky towards one another,
especially under conditions that promote the T-state.
enzyme - correct answer ✔✔are biological catalysts
Substrate - correct answer ✔✔a substrate is converted to a product and is
catalyzed by an enzyme.
product - correct answer ✔✔outcome of a reaction
active site - correct answer ✔✔a region on an enzyme that binds to a protein or
other substance during a reaction.
graded A+
Units and labels of the oxygen binding curve to portray myoglobin and
hemoglobin. Differences - correct answer ✔✔x is partial pressure O2 (pO2)
y fractional saturation (% saturation)
myoglobin, low p50, hyperbolic
hemoglobin, high p50, sigmoidal
If a hemoglobin is in the T state, how does its affinity for oxygen compare to that
of
hemoglobin in the R state? - correct answer ✔✔T has a lower affinity than the R
state hb
How does 2,3 BPG increase the ability of hemoglobin to release oxygen to the
tissues? - correct answer ✔✔By binding to the central cavity and preventing the
02-induced conformational changes, 2,3-BPG causes the T-state to be favored
state. Hb is therefore better able to release O2.
Explain how a) acidification of the blood and b) increasing carbon dioxide in the
blood
each change the affinity of hemoglobin for oxygen. - correct answer ✔✔Lowering
the pH and increasing the CO2 concentration favor the T-state, lowering the
affinity of Hb for 02. Protonation of Hb (lowering the pH) and carbamylation of Hb
, increasing the CO2 concentration promote the formation of T-state stabilization
ionic interactions
How does the fetus win out in the competition for the mother's oxygen? Next
question: A
smoker is pregnant and carrying a fetus. Assuming the 2,3 BPG could cross into
the fetal blood,
what effect would it have on the fetus? - correct answer ✔✔Fetal Hb
(alpha2,gamma2) is an R-state and does not bind in comparison to adult
Hb(alpha2,beta2)(T-state) and so a smoker or someone with asthma has increase
amount of 2,3 BPG and so the fetus will get the most oxygen. If the 2,3 BPG was in
the fetus bloodstream it wouldn't matter because it wouldn't bind.
What is the molecular basis of sickle cell anemia? - correct answer ✔✔A single
amino acid substitution (Valine instead of Aspartic Acid in position 6 of the beta
chains) causes neighboring hb molecules to become sticky towards one another,
especially under conditions that promote the T-state.
enzyme - correct answer ✔✔are biological catalysts
Substrate - correct answer ✔✔a substrate is converted to a product and is
catalyzed by an enzyme.
product - correct answer ✔✔outcome of a reaction
active site - correct answer ✔✔a region on an enzyme that binds to a protein or
other substance during a reaction.
