Transport Of Oxygen Flashcards
State the definition of Haemoglobin?
A group of chemically similar molecules found in many different organisms found in red blood cells
Explain the structure of Human Haemoglobin
A protein with 4 polypeptide chain. In each chain, there is a haem group containing Fe2+. Each Fe2+ can bind with an oxygen so each haemoglobin can carry 4 oxygen molecules
Explain what happens when oxygen binds
As first Oxygen molecule binds, it changes the shape of the tertiary structure of the haemoglobin molecule and this makes it easier for the oxygen molecules to bind. This is the co operative nature of oxygen binding
Explain when the graph curves to the right
It has a lower affinity for oxygen than human haemoglobin. It dissociates at relatively high partial pressures of oxygen. At any given partial pressure of oxygen, more oxygen released to respiring cells. Organisms with high rates of aerobic respiration have this
Explain when the graph curves to the left
It has a higher affinity for oxygen than human haemoglobin. This becomes fully saturated at lower partial pressures of oxygen. This is important for organisms living in oxygen depleted areas (water / high altitude)
What happens to haemoglobin in a higher oxygen environment?
Haemoglobin has a lower affinity for oxygen- Releases more oxygen at cells- Useful for animals with a high rate of respiration- E.g. small mammals have a higher SA:V so they lose more heat per gram maintaining an internal temperature
What happens to haemoglobin in a lower oxygen environment?
Lower partial pressure for oxygen in the lungs - Haemoglobin has a higher affinity for oxygen- Able to load oxygen at a lower partial pressure of oxygen
What does Affinity for Oxygen mean?
Tendency a molecule has to bind with oxygen
What does an Oxygen Dissociation Curve show?
It shows how saturated the haemoglobin is with oxygen at any given partial pressure of oxygen
