transport of oxygen

• Red blood cell


  Contains hemoglobin to transport oxygen in the blood
• Hemoglobin


  A quaternary structure protein with four polypeptide chains, each containing a heme group with iron that binds oxygen
• There are different types of hemoglobin found in different organisms and tissues
• Myoglobin


  Able to store and hold onto oxygen even at very low partial pressures of oxygen
• Affinity


  The ability of hemoglobin to attract and bind oxygen
• Saturation


  When hemoglobin holds the maximum amount of oxygen it can bind
• Loading/Association


  When oxygen is binding to hemoglobin
• Unloading/Dissociation


  When oxygen is detaching or unbinding from hemoglobin
• Oxyhemoglobin dissociation curve


  • Sigmoid (S-shaped) curve
  • At high partial pressures, hemoglobin is almost 100% saturated with oxygen
  • At low partial pressures, hemoglobin is only about 50% saturated with oxygen
• Cooperative binding


  The first oxygens that bind to hemoglobin are difficult, but once bound, it becomes much easier for subsequent oxygens to bind
• Bohr effect


  The effect of carbon dioxide on hemoglobin's affinity for oxygen - high CO2 makes the blood more acidic, shifting the curve to the right and decreasing hemoglobin's affinity for oxygen
• High CO2 partial pressure

  Oxyhemoglobin dissociation curve shifts to the right, decreasing hemoglobin's affinity for oxygen
• Low CO2 partial pressure

  Oxyhemoglobin dissociation curve shifts to the left, increasing hemoglobin's affinity for oxygen
• Fetal hemoglobin


  • Has a higher affinity for oxygen compared to adult hemoglobin, allowing the fetus to extract oxygen from the mother's blood
• Llama hemoglobin


  • Has a higher affinity for oxygen compared to human hemoglobin, allowing llamas to function at high altitudes with low oxygen partial pressures
• Dove hemoglobin


  • Has a lower affinity for oxygen compared to human hemoglobin, allowing doves to readily unload oxygen to their high-metabolism tissues during flight
• Earthworm hemoglobin


  • Has a higher affinity for oxygen compared to human hemoglobin, allowing earthworms to extract oxygen from the low-oxygen environments they live in underground