OXYHAEMOGLOBIN CURVE

Question 1

describe the quaternary structure of haemoglobin

Answer 1

4 polypeptide chains linked together
almost a spherical molecule
each polypeptide is associated with a haem group containing an Fe2+ ion
each Fe2+ ion can combine with one oxygen molecule
hydrophilic side chains face out and hydrophobic side chains face in
this makes it soluble and good for transport

Question 2

what is affinity for oxygen

Answer 2

ability of haemoglobin to attract or bind to oxygen

Question 3

what is saturation of haemoglobin

Answer 3

when haemoglobin is holding the maximum amount of oxygen that it can bind to

Question 4

what is loading / association of haemoglobin

Answer 4

the binding of oxygen to heamoglobin

Question 5

what is unloading / dissociation of haemoglobin

Answer 5

when o2 detaches / unbinds from haemoglobin

Question 6

what is the partial pressure of o2

Answer 6

po2 means oxygen concentration

Question 7

what is the partial pressure of co2

Answer 7

pco2 means carbon dioxide concentration

Question 8

what does haemoglobins affinity for oxygen depend on

Answer 8

po2
o2 associates with haemoglobin to form oxyhaemoglobin where there is a high po2

Question 9

describe the oxyhaemoglobin dissociation curve

Answer 9

o2 is loaded in regions with high partial pressure of o2 e.g. alveoli
and unloaded in areas of low partial pressure of o2 e.g. respiring cells

Question 10

what is cooperative binding

Answer 10

the cooperative nature of o2 binding to haemoglobin is due to haemoglobin changing shape when the first o2 binds. this makes it easier for further o2 to bind

Question 11

what is the bohr effect

Answer 11

when a high concentration of co2 causes the oxyhaemoglobin curve to shift to the right.
affinity for oxygen decreases as the acidic co2 changes the shape of the heaemoglobin