Indirect activity of CO2 is a result of increased concentration of which chemical species?

1.Indirect activity of CO2 is a result of increased concentration of which chemical species?
A) BPG     
b) H+
 c) heme iron
d) distal His

 2. Direct activity of CO2 is a result of binding to which molecular feature?
A) the heme group
b) the N-terminal ends of the 4 polypeptide chains
c) the central cavity
d) the proximal His

3. The sigmoidal, cooperative binding curve commonly observed for hemoglobin is a result of:
a) competition between CO2 and O2 for heme binding.
B) competition between heme and distal His for O2 binding
c) competition between BPG and CO2 for binding at the central cavity site
d) T to R transition

4. Hemoglobin has a tendency to release its oxygen to the tissues because:
 a) in this region pH is high and O2 concentrations are low
 b) in this region both pH and O2 concentrations are low
c) in this region both pH and O2 concentrations are high
d) there is much BPG in this region

5. Which statement about fetal hemoglobin is not true?
A) fetal hemoglobin has gamma chains instead of beta chains
b) fetal hemoglobin binds BPG less strongly than maternal hemoglobin
c) fetal hemoglobin binds oxygen less strongly than maternal hemoglobin
d) fetal hemoglobin binds oxygen more strongly than maternal hemoglobin

6. Which process is most responsible for the sickling of cells seen in sickle cell disease?
A) aggregation of the oxygenated R form of hemoglobin-S to form insoluble fibers
b) aggregation of the deoxygenated T form of hemoglobin-S to form insoluble fibers
c) Hemoglobin-S does not contain heme
d) Hemoglobin-S contains a mutant form of heme which will not bind oxygen

7 A person with sickle-cell trait is very unlikely to catch which disease?
 A) malaria
 b) colon cancer
c) avian flu
d) whooping cough

8. A person with a genetic defect which results in the synthesis of an insufficient amount of the alpha chain of hemoglobin is said to have which disease?
A) alpha thalassemia
b) beta thalassemia
c) pernicious anemia
d) Crohn’s disease

 9.The dominant motif found in hemoglobin and myoglobin is:
a) twisted beta sheet
b) beta barrel
c) helix-loop-helix
 d) 7-TM

10. Myoglobin has how many polypeptide chains?
A) 1              b) 2                 c) 3                        d) 4

11. Structurally and functionally, hemoglobin closely resembles a(n)
a) transmembrane protein
 b) mucopolysaccharide
 c) bile salt
d) allosteric enzyme

12. The oxygen binding site in hemoglobin and myoglobin is called:
a) BPG
 b) heme
c) proximal-His
d) N-terminal carbamate

13. The proximal His residue in hemoglobin and myoglobin binds to which atom or molecule?
A) CO2            b) O2                   c) Fe                       d) BPG
14. The distal His residue in hemoglobin and myoglobin binds to which atom or molecule?
 A) CO2              b) O2                 c) Fe               d) BPG
15. BPG binds to:

a) N-terminal carbamate                 b) proximal His                      c) heme group                 d) central cavity