Hemoglobin Recorded Lecture: Detailed Study Guide
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The P50 for adult hemoglobin (Hgb A) vs P50 for fetal hemoglobin (in mmHg); lower P50
means higher or lower affinity for O2; why is P50 useful; what is definition of P50, what
does it mean

Factors that cause a left and right shift in Oxy-Hb; factors that cause left (and upward) vs.
down and right in CO2 curve
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Oxy-Hb curve: label axes, PO2 at mixed venous point and % saturation, label where O2
loading vs. unloading, what is ICU point and where on curve (why is it significant);
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How does structural properties of Hb molecule give rise to the sigmoidal shape curve?
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Wavelength of light that Hb absorbs most light (Red 660 nm)
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Bohr vs Haldane matching; low PCO2 in lungs facilitates O2 loading (Bohr), high PO2 in
lungs facilitates CO2 unloading (Haldane); High PCO2 in tissues facilitates O2 unloading
(Bohr); describes how O2 conc. can determine Hb affinity toward CO2 (Haldane); describes
how CO2 and H ion conc can determine Hb affinity toward O2 (Bohr)

Pulse oximetry is based upon what law and is based upon the different absorption spectra of
oxy/deoxyhemoglobin with oxyhemoglobin absorbing more light in what spectra.

So fascinating…. Each human red blood cell contains approximately 270 million of these
hemoglobin biomolecules, each carrying four heme groups (individual proteins). Hemoglobin
comprises about a third of the total RBC volume. How many

Why is the curve sigmoidal; what happens when one subunit becomes oxygenated; what is
positive cooperativity; what are the two forms R and T (where do they exist under what
conditions and how does the molecular conversion affect Hb affinity for oxygen). When the
first O2 molecule binds the R form is favored which exposes more binding sites and
increases O2 affinity 500-fold; what conditions favor the R vs. T form