Hemoglobin Flashcards
1
Q
Composition
A
4 polypeptides (2alpha and 2 beta)
2
Q
Forms
A
T (taut): low affinity for O2
R (relaxed): high affinity for O2 (x300)
“Taut in Tissue, Relaxed in Respiratory”
3
Q
Regulation of hemoglobin by O2
A
Positive cooperativity
negative allostery
4
Q
What favors taut form?
A
High Cl-, H+, CO2, 2,3-BPG and temprature.
Shifts dissociation to the right,
leading to O2 unloading.
5
Q
Fetal hemoglobin
A
2alpha and 2gammas
Lower affinity for 2,3-BPG than adult
Thus higher affinity for O2
