Red blood cells contain hemoglobin to transport oxygen in the blood
Hemoglobin
A quaternary structure protein containing multiple polypeptide chains, each with a heme group that can bind oxygen
Key phrases
Affinity
Saturation
Loading/Association
Unloading/Dissociation
Oxyhemoglobin dissociation curve
Sigmoid (S-shaped) curve
High partial pressure of oxygen - almost 100% saturation
Low partial pressure of oxygen - around 50% saturation
Bohr effect
The effect of carbon dioxide on hemoglobin's affinity for oxygen - high CO2 makes the blood more acidic, shifting the dissociation 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
Different types of hemoglobin
Fetal hemoglobin (higher affinity)
Llama hemoglobin (higher affinity at low oxygen pressures)
Dove hemoglobin (lower affinity to facilitate unloading for high metabolism)
Earthworm hemoglobin (higher affinity for low oxygen environments)
Different animals have evolved different types of hemoglobin to adapt to their environments and oxygen needs
Affinity
the ability of a haemoglobin to attract or bind to oxygen
saturation
When haemoglobin is holding the maximum amount of oxygen it can bind
