Haemoglobin Flashcards
Transport of O2, Structure, Oxygen dissociation curve, Bohr shift
Why does the body use haemoglobin?
The solubility of O2 in solutions is low so we have an oxygen carrying molecule (Hb)
What type of protein is Hb?
Quaternary - Has four subunits each containing a haem group
Why can Hb carry four O molecules?
Each haem group can combine with one O molecule
When oxygen combines with Hb the substance formed is called…
Oxyhaemoglobin
The amount of a particular gas in a mixture of gases or a solution
Partial pressure
When oxygen is taken up by Hb
Loading
When oxygen is released up by Hb
Unloading
A natural attraction to somehing
Affinity - Hb loads oxygen because it has a high affinity for it
Oxygen dissociation curve
The more oxygen there is the more oxygen is taken up by Hb (e.g. High pO2 at the lungs = high affinity so Hb loads, Lower pO2 in tissue = low affinity so Hb unloads)
The effect of increased respiration on oxygen dissociation:
. Tissue cells respire quickly
. Respiration uses the O2 surrounding the tissue
. Reduces the pO2 to a level lower than normal
. The Hb will become more dissociated (less saturated) and more oxygen will be released from the Hb to the tissue cells
Oxygen dissociation curve shifts to the right
Bohr shift
In high concentrations of CO2 Hb’s affinity for oxygen is..
Lowered
If CO2 levels increase the saturation of Hb…
Decreases
Why does Hb have a lower affinity to O2 at high levels of CO2?
When CO2 dissolves in the blood it makes the blood acidic lowering the pH, as Hb is a protein a change in pH slightly alters the tertiary structure
How many types of basic Hb is there?
3
