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18 Cards in this Set
- Front
- Back
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What kind of iron is found in heme?
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Fe2+
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what kind of iron is found in methemoglobin?
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Fe3+ iron, cannot bind O2
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What has a higher O2 affinity, fetal or maternal hemoglobin?
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fetal
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What is the primary factor in determining percent hemoglobin saturation?
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this is directly related to Po2 in blood.
(Pao2) |
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what chain is affected in sickle cell disease? what AA change?
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this is a valine instead of a glutamic acid in the beta chain of heme
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For what pressures of PO2 is the oxygen-hemoglobin dissociation curve steepest?
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0-40 mmHg
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where does the oxygen-hemoglobin dissocation curve being to level off? at what PO2's?
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from 60-100mmHg
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What does the P50 represent on the hemoglobin-oxygen dissociation curve?
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this represents the point where 50% of Hb is bound by O2
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How low of a PO2 in the alveoli is tolerable without really affecting carrying capacity?
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60mmHg, as shown by the oxygen-hemoglobin dissociation curve
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What does a RIGHT shift in the O2-hemoglobin dissociation curve represent?
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this represents a decrease in Hb affinity for oxygen, so greater unloading of O2 even at higher Po2's
shifts P50 to higher pressures |
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What things cause a right shift in the oxygen-hemoglobin dissociation curve?
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a decrease in pH (due to high Co2)
an increase in temperature (like in exercise) and an increase in 2,3 DPG (BPG). see in chronic hypoxia |
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What does a LEFT shift of the O2-hemoglobin dissociation curve represent?
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this represents an increase in the affinity of Hb for O2 at lower partial pressure.
shifts P50 to a lower pressure |
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What things can cause a left shift in the O2-hemoglobin dissociation curve?
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this can be caused by a decrease in temp
a decrease in 2,3 DPG (due to lower RBC metabolism) or an increase in PH (due to low CO2 pressure) |
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What are the 3 ways that CO2 is transported in the body? which is the most prominent?
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Dissolved (5%)
Bound to Hb (3%) As bicarbonate (H2CO3) 90% |
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What is the solubility constant for O2?
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.003ml O2/100ml blood/mmHg
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what is the role of carbonic anhydrase? where is it found?
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this is used to convert CO2 and H2O into H2CO3 (bicarbonate)
this is found in RBCs |
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What is the role of the Cl-/HCO3- exchanger? (or band 3 protein)
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this is found in RBC's, it pumps out the HCO3- that is produced when H2CO3 degrades in RBC's
the H+ stays in the RBC's bound to deoxyhemoglobin |
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How does the Cl-/HCO3- exchanger work in the lungs?
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the H+ is release from deoxyhemoglobin
HCO3- is brought back in, via the exhanger H2O and CO2 are produced by the breakdown of the newly reformed H2CO3 H20/CO2 are expired by the lungs |
