Hemoglobin Flashcards
Each red blood cell in the body contains approximately _____ molecules of hemoglobin.
280 million
What is the predominant form of hemoglobin in the adult?
hemoglobin A1 (alpha2 beta2)
What is the predominant form of hemoglobin in the fetus?
hemoglobin F (alpha2 gamma2)
What happens when no alpha chain is present?
death
What constitutes the heme prosthetic group?
a protoporphyrin ring bound to iron
What is allosteric regulation of hemoglobin?
when hemoglobin binds to oxygen, it changes its configuration, increasing its binding affinity for more oxygen molecules
What is the excited form of hemoglobin called?
taut/T form
What is the relaxed form of hemoglobin called?
R form
Name the 3 main factors that can shift the oxygen dissociation curve.
1) pH
2) temperature
3) intracellular 2,3‐BPG concentration
The oxygen affinity of hemoglobin increases over a pH
range of ____.
6‐8.5
The oxygen affinity of hemoglobin ____ over a pH
range of 6‐8.5.
increases
The oxygen dissociation curve shifts to the ____ in alkaline situations because oxygen is held more tightly to hemoglobin.
left
The oxygen dissociation curve shifts to the ____ in acidic situations because oxygen is released to the tissues more easily.
right
What is the Bohr effect?
oxygen is more easily released from hemoglobin at acidic pHs
Hemoglobin’s oxygen affinity varies ____ with temperature.
inversely
Hemoglobin’s oxygen affinity varies inversely with _____.
temperature
At higher temperatures, more oxygen is _____ and less is ______.
unloaded to tissues; bound by hemoglobin
At ______, more oxygen is unloaded to tissues and less is bound by hemoglobin.
higher temperatures
What is the normal concentration of 2,3-DPG in an RBC?
5mmol/L
How does 2,3-DPG lead to decreased affinity of hemoglobin to oxygen?
it binds to deoxyhemoglobin and stabilizes it in the T configuration
Where are the alpha hemoglobin genes located?
chromosome 16
How many alpha-like hemoglobin genes are there?
4 copies
Where are the beta hemoglobin genes located?
chromosome 11
How many beta-like hemoglobin genes are there?
2 copies
