Slides in this set
What it the role of haemoglobin?
The role of haemoglobin is to transport
oxygen. To be efficient at transporting oxygen
it must be:
- Readily associated with oxygen at the
surface where gas exchange takes place.
- Readily dissociate from oxygen at tissues
requiring it.…read more
Structure of haemoglobin
Haemoglobin molecules are made of 4 subunits:
Under the right conditions, oxygen(O2)bind at the
centre of each haem molecule
The changes in the structure allows
more (O2) molecules to bind. This is
known as co-operative bonding.
When an (O2) molecule binds to the haem group
Each chain surrounds
the structure a haem molecule
of the haemoglobin changes. that holds a
single iron atom…read more
Affinity for oxygen
Haemoglobins with a high affinity for oxygen:
Take up oxygen more easily but release it less
Haemoglobin with a low affinity for oxygen:
Take up oxygen less easily but release it more
Effects of CO2 concentration
When carbon dioxide is present, haemoglobin has a reduced
The greater the concentration of CO2, the more readily the
haemoglobin releases its oxygen.
- At the gas exchange surface the level of CO2 is low because it
diffuses across the exchange surface and is expelled. The affinity
for oxygen is increased which means that oxygen is readily
loaded by haemoglobin.
- In respiring tissues the level of CO2 is high. The affinity for
oxygen is reduced which means oxygen is readily unloaded from
haemoglobin into the muscle cells.…read more