Mass Transport Flashcards
What is meant by loading/associating haemoglobin with O2?
Process by which haemoglobin binds to O2 (in the alveoli, lungs) to for, oxyhaemoglobin
What is meant by unloading/dissociating O2 with haemoglobin?
Process by which haemoglobin releases O2 (in the respiring tissues)
What does it mean if haemoglobin has a high affinity for O2?
Haemoglobin takes up O2 more easily and releases it less easily
What does it mean if haemoglobin has a low affinity for O2?
Haemoglobin takes up O2 less easily but releases it more easily
What is meant by affinity?
Chemical attraction
What is the reversible equation for haemoglobin and O2?
Haemoglobin + O2 = oxyhaemoglobin
How does carbon monoxide affect the uptake of O2 by haemoglobin?
Haemoglobin has a higher affinity for carbon monoxide than oxygen (a stronger chemical attraction) therefore carbon monoxide binds/associates to haemoglobin preventing O2 from doing so this means O2 is not transported to respiring tissues which need it for respiration so can lead to unconsciousness
Why do different organisms have different haemoglobin molecules?
Different primary structure, leading to a different quaternary structure as ever haemoglobin has different binding properties depending on the species
What is meant by partial pressure?
Measured in kPa, it is a measure of the pressure given off by a particular gas in a given space (for example O2)
What is meant by positive cooperativity?
The first molecule makes the binding of the second molecule easier, and so on
The further to the left a curve is…
….the greater its affinity of haemoglobin for O2 (readily loads O2 and unloads it less easily)
What is meant by the Bohr Effect?
Shows that hemoglobins affinity for oxygen is related both to acidity and to the concentration of carbon dioxide shown on the oxygen–haemoglobin dissociation curve
What should you refer to in a question about O2 dissociation?
Partial pressure of O2
Position of the curve
Affinity for O2
O2 saturation
What is the effect of temperature on the curve?
As temp increases the blood becomes less saturated with O2, so haemoglobin has a lower affinity for O2, the curve will be shifted to the right
What is haemoglobin?
A protein with a quaternary structure found in red blood cells adapted to transport O2
