What is the allosteric effect on O2 binding to the second subunit of hemoglobin after the first subunit bindsafter O2 binding?to 02? What state would hemoglobin beO A decrease in affinity of hemoglobin for 02: T-StateO An increase in affinity of hemoglobin for O2: T-StateAn increase in affinity of hemoglobin for 02; R-StateO A decrease in affinity of hemoglobin for O2; R-State

Haemoglobin can bind hydrogen ion, oxygen molecule and carbon dioxide to itself. All these bindings…

What is the allosteric effect on O2 binding to the second subunit of hemoglobin after the first subunit binds to 02? What state would hemoglobin be in after O2 binding? O A decrease in affinity of hemoglobin for O2: T-State () An increase in affinity of hemoglobin for O2: T-State An increase in affinity of hemoglobin for 02; R-State OA decrease in affinity of hemoglobin for O2; R-State

What is the allosteric effect on O2 binding to the second subunit of hemoglobin after the first subunit binds to 02? What state would hemoglobin be in after O2 binding? O A decrease in affinity of hemoglobin for O2: T-State () An increase in affinity of hemoglobin for O2: T-State An increase in affinity of hemoglobin for 02; R-State OA decrease in affinity of hemoglobin for O2; R-State

Human Physiology: From Cells to Systems (MindTap Course List)

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter11: The Blood

Section: Chapter Questions

Problem 1SQE

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Similar questions

A new oxygen transport protein that exhibits cooperative binding has been isolated and is beingstudied in the lab. Calculate the KD value if Y = 0.76 when pO2 = 18 torr (assume n = 2.5). Howdoes this compare to the KD value for hemoglobin? Does this protein bind more or less tightly tooxygen compared to hemoglobin?
) Dr Merrick is so excited to know the affinity constant Kd values for O2 binding to mammoth OBP and elephant hemoglobin at pH=7, that he starts speculating about the kinetics of binding to O2. If the ka value of mammoth EHb-O2 complex was the same as the ka value of mammoth OBP-O2 complex, what would be the ratio between the kd values of these complexes? Explain your reasoning. Hint: we are looking for the ratio kd(EHb)/kd(OBP) at pH=7.
Which of the following statements is false concerning the structure of hemoglobin? a. The binding of BPG stabilizes the T-state of Hb b. The R-state of Hb is favored under environments of high concentrations of O2 c. Hemoglobin's affinity for oxygen increases as protons ionize from the N-terminal tails d. Hemoglobin is stabilized in the low affinity state in the presence of high concentration of protons e. Hemoglobin favors the R-state in basic environments
What qualitative effect would you expect each of the following to have onthe P50 of hemoglobin?(a) Increase in pH from 7.2 to 7.4(b) Increase in PCO2 from 20 to 40 mm Hg(c) Dissociation into monomer polypeptide chains(d) Decrease in 2,3-BPG concentration from 7 mM to 5 mM in red cells.
Hemoglobin from different species can have different numbers of subunits. Let's consider three hemoglobin molecules: n = 1, n = 4, and n = 8, where each subunit has an oxygen P50 = 30 torr. (Recall that Pso is essentially a Kp and that oxygen partial pressure (torr) is directly proportional to concentration.) Which molecule transports the most O2 between the lungs (pO2 = 100 torr) and peripheral tissues (pO2 = 30 torr)? Please justify your answer.
In one type of hemoglobin mutant the amino acid change generates a strong ionic interaction stabilizing the T state conformation, but only under conditions of lower pH, e.g., at pH 7.2 compared to pH 7.6. Explain what effect this mutation would have on the amount of O2 delivered to the tissue. More O2 delivered to the tissue because the R-T equilibrium would be shifted to the T state in tissues. More O₂ delivered to the tissue because the R-T equilibrium would be shifted to the T state in lungs. Less O2 delivered to the tissue because the R-T equilibrium would be shifted to the T state in lungs. Less O₂ delivered to the tissue because the R-T equilibrium would be shifted to the T state in tissues. More O2 delivered to the tissue because the R-T equilibrium would be shifted to the R state in tissues.
Suppose you mutate the proximal histidine of hemoglobin to glycine. You study the behavior of this mutant hemoglobin in the presence of 10 mM imidazole; the imidazole molecule can substitute for the proximal histidine chain and bind to the heme iron just as histidine does. a) Which state (T or R) will this mutation favor? b) Will oxygen binding to this state be tighter or weaker than oxygen binding to the same state of the wildtype hemoglobin? (note: wildtype means refers to the phenotype of the typical form of a species as it occurs in nature) c) Will this mutant still display significant cooperativity?
Suppose you mutate the proximal histidine of hemoglobin to glycine. You study the behavior of this mutant hemoglobin in the presence of 10 mM imidazole; the imidazole molecule can substitute for the proximal histidine chain and bind to the heme iron just as histidine does. a) Which state (T or R) will this mutation favor? b) Will oxygen binding to this state be tighter or weaker than oxygen binding to the same state of the wildtype hemoglobin? (note: wildtype means refers to the phenotype of the typical form of a species as it occurs in nature) c) Will this mutant still display significant cooperativity (Please provide clear and sufficient explanation for each part, thank you!)
How does the difference between the-chain and the -chain of hemoglobin explain the differences inoxygen binding between Hb A and Hb F?
From the figure of O2 binding to myoglobin and hemoglobin (ignore the linemarked as T) as described in lecture (shown below) answer the following questions. a) Estimate the P50 for myoglobin from the plot. Show how this estimation isdetermined from the binding curve above. ( The first ghraph) b)Using YO2 = PO2/P50 + PO2 , calculate the fraction of O2 bound for myoglobin at 1 torr. (2nd graph) c)Using the binding curve on the previous page, show how you can estimate whatfraction of hemoglobin is bound near tissues at a pO2 of 30 torr and provide this value. If the pH were lowered, will the amount of O2 bound to hemoglobin at 30 torr increaseor decrease? Explain why this is so based on how this changes hemoglobin structure. If 2,3-BPG were added to the solution, will the amount of O2 bound to hemoglobin at30 torr increase or decrease? Explain why this is so based on how this changes hemoglobinstructure.
One molecule of 2,3-BPG binds to one tetramer of hemoglobin in a central cavity of the hemoglobin molecule. Is the interaction between BPG and hemoglobin stronger or weaker than it would be if BPG bound to the surface of the protein instead? Explain your answer (hint: think about how these different situations affect the dielectric constant).
What is the role of 2, 3-Bisphosphoglycerate (2,3-BPG) in the function of haemoglobin as an oxygen carrier molecule? Explain the binding mechanism and effect of 2,3-BPG leading to the reduced oxygen binding affinity for haemoglobin and transitions in the T (deoxygenated) and R (oxygenated) states of haemoglobin.