Hb is 70% saturated in arterial blood

As the hemoglobin molecule loads and unloads O₂ the individual globin chains in the hemoglobin molecule move on each other

When O₂ is unloaded the βchains are pulled apart, permitting entry of the metabolite 2,3‐diphosphoglycerate (2,3‐DPG) and resulting in a lower affinity of the molecule for O₂

The P50 (i.e. the partial pressure of O₂ at which haemoglobin is half saturated with O₂) of normal blood is 26.6 mmHg^

50% of the membrane is cholesterol

Spectrin and ankyrin are extracellular proteins that reinforce the membrane

Alterations in serum lipids do not influence the red cell membrane

Inherited defects in membrane proteins can cause hereditary spherocytosis and elliptocytosis

1

2

3

4

It enhances the release of oxygen from hemoglobin

It provides a source of glucose for the RBC.

It is unnecessary for RBC survival.

It is the least abundant of all organophosphates in the RBC.

α and β

α and δ

α and γ

α and ε

Inducing more pluripotent stem cells into the

erythroid lineage

Stimulating EPO production by the kidney

Increasing the number of RBC mitoses

Stimulating the production of fibronectin by

macrophages of the bone marrow

The number of divisions of a normoblast

The formation of pores in sinusoidal endothelial cells

for marrow egress

The time between mitoses of normoblasts

The production of antiapoptotic molecules by

erythroid progenitors

Binds to the heme moiety, blocking the binding of

oxygen

Binds simultaneously with oxygen to ensure that it

stays bound until it reaches the tissues, when both molecules are released from hemoglobin

Binds to amino acids of the globin chain, contributing to a conformational change that inhibits oxygen from binding to heme

Oxidizes hemoglobin iron, diminishing oxygen binding and promoting oxygen delivery to the tissues

α and β

α and δ

α and γ

α and ε