1. O-saturation curves of fetal and maternal blood are markedly different when m
ID: 3506548 • Letter: 1
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1. O-saturation curves of fetal and maternal blood are markedly different when measured under identical conditions. Fetal hemoglobin contains two y-subunits paired with two -subunits (a2%) as opposed to the . .configuration of maternal hemoglobin 1.0 +BPG HbA +BPG 10 (kPa) a) Does HbA of HbE have higher affinity for oxygen under physiological conditions? Explain your answer b] What is the physiological significance of the different Oz affinities? c)When all the BPG is carefully removed from samples of HbA and HbE, the measured 02-saturation curves (and consequently the O2 affinities) are displaced to the left. However, HbA now has a greater affinity for oxygen than does HbE. When BPG is reintroduced, the O2-saturation curves return to normal, as shown in the graph above. What is the effect of BPG on the O2 affinity of hemoglobin? How can the above information be used to explain the different O2 affinities of fetal and maternal hemoglobin? e 0.b HNA BPG 12:34 9/23/20Explanation / Answer
A) foetal hemoglobin have higher affinity than adult hemoglobin this change results in less binding of 2 3 -BPG to foetal as a result oxygen will bind to it at higher affinity than adult hemoglobin
B)different o2 affinities
It makes sense that HBf have higher oxygen affinity as oxygen have to be transferred from mother to foetus. The binding of oxygen by hemoglobin is a dynamic process with o2 binding and releasing when a o2 molecule is released from HBA it is more likely to be bound by HBF than another HBA
C)BPG when bound to hemoglobins it decreases the oxygen affinity of that molecule by stabilising the deoxy form the above information indicates that binding of BPG to HBA has greater effect than binding to HBF.this suggests BPG binds more tightly to HBA.stronger binding of BPG by HBA than HBF indicates that the residues lining the central cavity of deoxy HBA are different from HBF
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