White Review Flashcards
When oxygen binds to hemoglobin what happens to the iron atom
Causes a conformational change in which the iron atom moves into the plane of the heme ring (a 0.4 A change)
What does the movement of the iron cause within the Hb
the F8 proximal histidine to be pulled which changes the associated globin change
What must the binding of O2 be within the Hb
Reversible in order to allow the O2 to be attached in the lungs and detached at the tissue
How does O2 bind to Hb
In a cooperative fashion
T/F Conformational change in the heme ring following O2 causes conformational change in attached hemes making the affinity of O2 to the heme rings to increase
True
Is the pH of actively respiring tissues higher or lower then normal
Lower (more acidic)
What is the drop of pH in actively respiring tissue
0.2, 7.4 -> 7.2
What happens to the binding affinity of Hb for O2 as pH decreases
It also decreases
What happens in order to cause the release of the O2 from the Hb
A H+ is picked up from the tissue which causes a conformational change favoring the release of the O2
T/F Fetal Hb (HbF) needs to have a lower affinity to O2 then mother’s Hb
False, if it has a lower affinity O2 will not separate from maternal Hb causing fetal hypoxia
How does alpha globin chain affect Hb in fetal life
Excess gamma globin chains form gamma4 tetramers also known as Hb Bart’s
How does alpha globin chain affect Hb in adult life
Excess beta globin chains form beta4 tetramers also known as HbH
HbH disease affects how many genes
3 of the alpha genes are affected -a/–
What is HbH disease characterized by
Moderately severe anemia, Microcytic, hypochromic hemolytic anemia, hepatosplenomegaly, mild jaundice
What makes up Heinz bodies
HbH beta4 tetramers that precipitate slowly as red blood cells mature and age
