3. Mass Transport Flashcards
What is the process in which haemoglobin binds with oxygen?
Loading or associating
Where does loading or association take place?
In the lungs
What is the process called where haemoglobin releases oxygen?
Unloading or dissociating
What does a high affinity for oxygen mean?
It’s takes up more oxygen easily
But releases it less easily
What does haemoglobin with a low affinity for oxygen mean?
Takes up oxygen less easily, but releases it more easily
What is the role of haemoglobin?
To transport oxygen
To be efficient at transporting oxygen, haemoglobin must?
Readily associate with oxygen at the surface where gas exchange takes place
Readily dissociate from oxygen at tissues requiring it
What does haemoglobin shape do?
Changes in the presence of certain substances
What is an oxygen dissociation curve?
The saturation of haemoglobin with oxygen and the partial pressure of oxygen
What happens in the first stage of a dissociation curve?
Shape of haemoglobin makes it difficult for first oxygen to bind
At low oxygen concentrator little oxygen binds to haemoglobin
Gradient is shallow
What is the second stage?
The binding of the first oxygen changes the shape of the haemoglobin
More oxygens can now bind
What is the third stage?
Positive cooperativity= the first binding makes the second one easier
What happens in the last stage?
It is harder for the fourth molecule to bind
Less likely the oxygen will find an empty site to bind to
Graph flattens off
What does it mean when the curve is to the left?
The greater is the affinity of haemoglobin for oxygen
It loads oxygen readily but unloads it less easily
What does it mean when the curve is further to the right?
The lower the affinity of haemoglobin for oxygen
It loads oxygen less readily but unloads more easily
