University:
Eastern Kentucky University
Course:
CHE 111 | General Chemistry
Academic year:

2022
Views:

401

Pages:

3
Author:

Galaffi133

3401 Recitation Worksheet Week 7 1.) Where are hemoglobin and the myoglobin located in the body? 2.) Determine which statements apply to hemoglobin, myoglobin, or neither: a. Oxygen binds irreversibly to this molecule b. The binding pattern for this molecule is considered to be cooperative c. This molecule has a greater affinity for oxygen d. The oxygen dissociation curve is sigmoidal in shape e. This molecule delivers oxygen more efficiently to tissues f. The oxygen dissociation curve is hyperbolic in shape g. Carbon monoxide binds at an allosteric site, lowering oxygen binding affinity h. As oxygen binds to this molecule the shape of the molecule changes, enhancing further oxygen binding 3.) After a person spends a day or more at high altitude (with an oxygen partial pressure of 75 torr), the concentration of 2,3-BPG in that personÕs red blood cells increases. What effect would an increased concentration of 2,3-BPG have on the oxygen binding curve for hemoglobin? Explain why this adaptation would be beneficial for functioning well at high altitude. 4.) Which molecules are bound to hemoglobin when hemoglobin is in the R state? a. Fe2+ b. 2,3-bisphosphglycerate c. CO2 d. Fe3+ e. Oxygen 5.) Predict whether each of the following manipulations will increase or decrease the tendency of HbS molecules to polymerize in vitro. Give a brief a. Increase in partial pressure of oxygen b. Stripping of the HbS molecules of 2,3-BPG c. Increase in pH 6.) What is the physiological significance of the cooperative binding of oxygen by hemoglobin? 7.) The cooperative nature of hemoglobin can be understood using either the sequential model, in which each of the four subunits changes from T to R individually upon binding oxygen, or the MWC symmetry model, in which the whole tetramer shifts at once from T to R. What structural features of hemoglobin support each model? 8.) Explain why fetal hemoglobin has a higher affinity for oxygen than does maternal hemoglobin and why this is necessary for adaptation. 9.) Which of the following statements concerning the Bohr effect are true? a. Lowering the pH shifts the oxygen dissociation curve of hemoglobin to the right. b. The acidic environment of an exercising muscle allows hemoglobin to bind to O2 more strongly. c. The affinity of hemoglobin for O2 is diminished by high concentrations of CO2. d. In the lungs, the presence of higher concentrations of H+ and CO2 allows hemoglobin to become oxygenated. e. In the lungs, the presence of higher concentration of O2 promotes the release of CO2 and H+.