what is meant by a quaternary structure?

what is the role of haemoglobin?

how is haemoglobin adapted to its function?

In terms of haemoglobin, what does high affinity mean?

in terms of haemoglobin, what does a low affinity for oxygen mean?

in what direction does an oxygen dissociation curve move if haemoglobin has a high affinity for oxygen?

in what direction does the oxygen dissociation curve move if the oxygen has a low affinity for oxygen?