學士後西醫-普通生物及生化概論題庫下載題庫

血紅素有多種類型，正常人出生後有三種血紅素：

　　 1．血紅素A(HbA)：占成人血紅素的96%-98%，由一對α鏈和一對β鏈組成(α2β2)；

　　 2．血紅素A2(HbA2)：由一對α鏈和一對δ鏈組成(α2δ2)，占血紅素的2%～3%；

　　 3．胎兒血紅素(HbF)：由一對α鏈和一對γ鏈組成(α2γ2)，僅存在於胎兒血中，出生6個月後含量僅1%左右。

(C) 2,3-BPG interacts much more with hemoglobin A than hemoglobin F. This is because the adult β subunit has more positive charges than the fetal γ subunit, which attract the negative charges from 2,3-BPG. Due to the preference of 2,3-BPG for hemoglobin A, hemoglobin F binds to oxygen with more ...

血紅素有多種類型，正常人出生後有三種血紅素：

　　 1．血紅素A(HbA)：占成人血紅素的96%-98%，由一對α鏈和一對β鏈組成(α2β2)；

　　 2．血紅素A2(HbA2)：由一對α鏈和一對δ鏈組成(α2δ2)，占血紅素的2%～3%；

　　 3．胎兒血紅素(HbF)：由一對α鏈和一對γ鏈組成(α2γ2)，僅存在於胎兒血中，出生6個月後含量僅1%左右。

(C) 2,3-BPG interacts much more with hemoglobin A than hemoglobin F. This is because the adult β subunit has more positive charges than the fetal γ subunit, which attract the negative charges from 2,3-BPG. Due to the preference of 2,3-BPG for hemoglobin A, hemoglobin F binds to oxygen with more affinity, in average.

(D) In pregnant women, there is a 30% increase in intracellular 2,3-BPG. This lowers the maternal hemoglobin affinity for oxygen, and therefore allows more oxygen to be offloaded to the fetus in the maternal uterine arteries.

(E) 2,3-BPG is present in human red blood cells (RBC; erythrocyte) at approximately 5 mmol/L.