Respiratory q4 N*

[Roxanita]

Fetal and maternal erythrocytes have the same concentration of 2,3-bisphosphoglycerate. However, compared with maternal hemoglobin (HbA), fetal hemoglobin (HbF) has a higher oxygen affinity, which facilitates transplacental diffusion of oxygen. The presence of which of the following polypeptide chains in HbF accounts for this finding?

A) α Chains alone
B) β Chains alone
C) γ Chains
D) Both α and β chains

[Asclepius1]

Originally Posted by Roxanita

Fetal and maternal erythrocytes have the same concentration of 2,3-bisphosphoglycerate. However, compared with maternal hemoglobin (HbA), fetal hemoglobin (HbF) has a higher oxygen affinity, which facilitates transplacental diffusion of oxygen. The presence of which of the following polypeptide chains in HbF accounts for this finding?

A) α Chains alone
B) β Chains alone
C) γ Chains
D) Both α and β chains

My guess is C, the gamma chain that cause the increase affinity and causing the oxygen dissociation curve to shift to the left.