Unformatted text preview: CHEM 4511/6501 PS 6 Fall 10 ‐ Solutions 1. To solve, plot out the data and identify the concentration of ligand that corresponds to a θ value of 0.50. 2. To solve, plot out data. If one of the binding curves leads to a sigmoidal shape, then that is likely indicative of cooperative binding. 3. A. Protein B has a greater affinity for ligand X. Protein A will require a concentration of ligand X 3 orders of magnitude greater than that for protein B in order to achieve half‐saturation (and saturation) in binding. B. Protein A Ka is 106 M‐1; Protein B Ka is 109 M‐1 4. A. 1.3 x 10‐8 M B. 5 x 10‐8 M C. 7.5 x 10‐8 M D. 2.0 x 10‐7 M 5. A. Hyperventilation will help to eliminate CO2 from the lungs. This, however, has no affect on the ability of hemoglobin to bind O2 in the lungs, which already achieves near‐saturation in O2 binding. So there will be no change in the pO2 in the blood. B. Through the CO2/carbonic acid/bicarbonate buffer system in place in the blood, hyperventilation will result in a reduction of bicarbonate and H+ in the blood as excess CO2 is “blown off.” The result is an increase in pH (albeit temporary until additional CO2 is generated through metabolic respiration). The Bohr Effect predicts that this will lead to less efficient delivery to the tissues when the pH is increased. Thus, hyperventilation has the opposite of the intended effect. (It is also potentially dangerous and can lead to loss of consciousness while underwater, increasing the risk of drowning). 6. A. Decreases B. Increases C. Decreases D. Decreases 7. These observations suggest that the interactions between subunits are critical to the cooperative behavior of hemoglobin binding O2. 8. A. Memphis B. HbS, Milwaukee, Providence, and (probably) Cowtown C. Providence ...
View Full Document
- Fall '10
- Chemistry, ligand X. Protein, Decreases D. Decreases, Cowtown C. Providence, binding. B. Protein, hemoglobin binding O2.