Which statements is false concerning the binding of o2, co2 and/or protons to hemoglobin?
a. the high pka of the c-terminal h creates a salt bridge to a d residue in the b-subunits and stabilizes the deoxy form of hb
b. o2 and co2 bind to the fe of the heme group, but o2 is stabilized by the distal h residue and co2 is not
c. protons bind to several amino acids in the hb molecule
d. the n-terminal of the hb chains transport carbon dioxide
e. oxygen binding causes the fe to move into the porphyrin plane resulting in movement at the a1b2 and a2b1 interfaces