Heart and muscle cells, where myoglobin resides, maintains an intracellular pO2 of about 2.5 torr. Calculate the fractional saturation (for human myoglobin) if a small change (1 torr) in oxygen partial pressure occurs in either direction (ie what happens at 1.5 torr, what happens at 3.5 torr?) and explain how a small change in oxygen pressure dramatically changes the myoglobin oxygen binding.

Heart and muscle cells, where myoglobin resides, maintains an intracellular pO2 of about 2.5 torr. Calculate the fractional saturation (for human myoglobin) if a small change (1 torr) in oxygen partial pressure occurs in either direction (ie what happens at 1.5 torr, what happens at 3.5 torr?) and explain how a small change in oxygen pressure dramatically changes the myoglobin oxygen binding.

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

See similar textbooks

Similar questions

Using the Nernst equation, calculate the equilibrium potential for Ca2 and for C1 from the following sets of data: a. Given [ Ca2+ ]0=1mM,[ Ca2+ ]i=100nM, find Eca2+ b. Given [ Cl- ]0=110mM,[ Cl- ]i=100mM, find Ecl
If instead of using 3.5 µM myoglobin (receptor) you used half of this (that is, 1.75 µM myoglobin), what would be that value of the Kd, that you calculated ( how would it change)? Please explain so I can solve on my own :) (How does changing concentration of the receptor in a ligand-receptor binding experiment affect the dissociation constant?)
In a Myoglobin and azide ligand-receptor binding experiment, instead of using 3.5 µM myoglobin you used half of this (1.75 µM myoglobin), what would be that value of the Kd, that you calculated (how would the Kd change)?
In a rat cardiomyocyte, the levels of creatine, phosphocreatine, and free phosphate were found to be 37.6mM, 40.3mM, and 8.02mM, respectively. Given that the standard free energy change is –43.0 kJ/mol, what is the true free energy change for phosphocreatine hydrolysis in the cardiomyocyte described above?
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.
Calculate the percent oxygen saturation of myoglobin if 7 of 15 binding sites are occupied..
Estimate the flux (mg/cm2/s) by diffusion of estrogen (a steroid) through a lipid bilayer cell membrane when assuming the diffusion coefficient for estrogen across the lipid bilayer is 10^–6 cm2/s, and that the initial concentration of estrogen in the extracellular fluid is 1 ng/mL and 0 in the cytoplasm.
Sickle-cell hemoglobin (HbS) differs from normal human adult hemoglobin (HbA) by a single mutational change, Glu6 S Val, which causes the HbS molecules to aggregate under proper conditions. Under certain conditions, the HbS filaments that form at body temperature disaggregate when the temperature is lowered to 0°C. Explain.
Studies of oxygen transport in pregnant mammals have shown that the O2-saturation curves of fetal and maternal blood are markedly different when measured under the same conditions. Fetal erythrocytes contain a structural variant of hemoglobin, HbF, consisting of two γ and two β subunits (γ2β2), whereas maternal erythrocytes contain HbA (α2β2). (a) Which hemoglobin has a higher affinity for oxygen under physiological conditions, HbA or HbF? Explain. (b) What is the physiological significance of the different O2 affinities? (c) When all the BPG is carefully removed from samples of HbA and HbF, the measured O2-saturation curves (and consequently the O2 affinities) are displaced to the left. However, HbA now has a greater affinity for oxygen than does HbF. When BPG is reintroduced, the O2-saturation curves return to normal, as shown in the graph. What is the effect of BPG on the O2 affinity of hemoglobin? How can the above information be used to explain the different O2 affinities of…
In considering active transport by Na + -K + -ATPase at body temperature (37 o C), 3 Na+ are pumped out of the cell and 2 K + are pumped in for each ATP that is hydrolyzed to ADP + P i . Given that underyour experimental conditions, the DG for ATP hydrolysis is -10 kcal/mol, and that V is -60 mV, and that the pump maintains the internal Na + at 10mM, external Na + at 120 mM, internal K + at 120 mM and external K + at 8mM, what is the efficiency of the pump (i.e., what fraction of the energy available from ATP hydrolysis is required to drive transport at the provided levels)?
In a molecular disease of hemoglobin, Hemoglobin Rainier, Tyr 145β is replaced by Cys, which forms a disulfide bond with another Cysresidue in the same subunit. This prevents the formation of ion pairs that normally stabilize the T state. How does hemoglobin Rainier differ from normal hemoglobin with respect to (A)oxygen affinity, (B)the Bohr effect, and (C)the Hillcoefficient? Explain your answers.
Neutral sphingomyelinase 2 converts sphingomyelin into ceramide and phosphorcholine. What kind of enzyme is it? Assume Vmax is 35 µM min-1. When you provide 3.0 x 10-5 M of sphingomyelin, you observe an initial velocity of 6.0 µM min-1. Calculate the KM.