Question

Which of these is not found in myoglobin? A) alpha helix b) beta sheet c) heme group 1. d) globular folding pattern 2. Which statement about hemoglobin is not true? A) it is globular b) it contains helix- loop-helix c) it has three subunits d) it has heme groups 3. The molecule which binds in the central cavity of hemoglobin when it is deoxygenated is: a) CO2 b) heme c) BPG d) all of these 4. The transition of hemoglobin from its T-form to its R-form regluls in: a) Loss of BPG b) release of CO2 c) cooperative oxygen binding behavior d) conversion of alpha helix to beta sheet while the direct effect of 5. The indirect effect of CO2 is a result of formation of Co, is the result of the formation of A) heme, BPG B) alpha helix, beta sheet C) carbonic acid, N-terminal carbamate d) carbonic acid, BPG 6. The iron in heme in hemoglobin and myoglobin binds to oxygen. It also binds to a) BPG b) CO2 c) proximal His d) distal His The oxygen molecule which binds to the heme iron in hemoglobin and myoglobin also 7. binds to: a) BPG b) CO2 c) proximal His d) distal His 8. Which statement about sickle cell hemoglobin is not true? A) it is fibrous in its deoxygenated form b) it has Val instead of Glu in position 6 of the beta chain c) It has lost its heme groups d) it offers resistance against malaria 9. A person with sickle-cell disease would have about what % sickled cells? A) 100 % b) 50% c) 5% d) 1% 10. Beta thalassemia is named such because: a) the patient's hemoglobin contains mostly beta sheet. B) the patient lacks the gene for the beta subunit of hemoglobin, resulting in tetramers of the alpha subunit c) the patient lacks the gene for the alpha subunit of hemoglobin, resulting in tetramers of the beta subunit d) in beta thalassemia, the heme groups are bonded to beta barrel motifs

Answer 1

1. b) BETA SHEET IS NOT FOUND IN MYOGLOBIN

2. c) It has three subunits

3. d) all of these

4. c) cooperative oxygen binding behavior

5. d) carbonic acid, BPG

6. c) proximal histidine