Choose all of the following statements that accurately describe the structures of hemoglobin (Hb) and myoglobin (Mb)?
Question options:
A. The Hb tetramer contains four polypeptide chains (alpha-1, alpha-2, beta-1 and beta-2), each of which has a different amino acid sequence, and each of which is bound to a single heme prosthetic group in which a single iron ion is bound
B. Mb contains 8 separate alpha-helices, which by convention are labeled A-H
C. The Mb monomer contains a single polypeptide chain bound to a single heme prosthetic group in which a single iron ion is bound
D. A binding site for the heterotropic modulator bisphosphoglycerate contains positively charged amino and imidazole functional groups contributed by the two beta subunits in the R-state, when oxygen is bound to the heme groups
E. The structure and function of the binding site for oxygen in Mb more closely resembles that of the high-affinity binding site for oxygen seen in the R-state of Hb than the low-affinity binding site for oxygen seen in the T-state of Hb
