13.6 Transport of Oxygen in Blood

2, 3-Diphosphoglycerate (DPG)

Substance produced by erythrocytes during glycolysis; binds reversibly to hemoglobin, causing it to release oxygen

Deoxyhemoglobin (Hb)

Hemoglobin not combined with oxygen; reduced hemoglobin

Fetal Hemoglobin

Oxygen-carrying molecule with high oxygen affinity

Globin

Collective term for the four polypeptide chains of the hemoglobin molecule

Heme

Iron-containing organic complex bound to each of the four polypeptide chains of hemoglobin or to cytochromes

Hemoglobin

Protein composed of four polypeptide chains, each attached to a heme; located in erythrocytes and transports most blood oxygen

Hemoglobin Saturation

Percentage of hemoglobin that has O2 or any other gas bound to its iron moiety

Oxygen-Carrying Capacity

Maximum amount of oxygen the blood can carry; usually proportional to the amount of hemoglobin per unit volume of blood

Oxygen-Hemoglobin Dissociation Curve

S-shaped (sigmoid) relationship between the gas pressure of oxygen (partial pressure of O2) and amount of oxygen bound to hemoglobin per unit blood (hemoglobin saturation)

Oxyhemoglobin (HbO2)

Hemoglobin combined with oxygen

Percent Hemoglobin Saturation

The percentage of available hemoglobin subunits bound to molecular oxygen at any time