7.2 transport of oxygen by haemoglobin

Question 1

what does a oxygen dissociation curve show?

Answer 1

relation between oxygen saturation & partial pressure

Question 2

why is the initial curve shallow at the oxygen dissociation curve?

Answer 2

first O2 is difficult to bind as 4 subunits are closely united

Question 3

explain the meaning of positive cooperativity.

Answer 3

binding of 1st O2 exposes more binding sites

Question 4

why does the curve levels off at the end of the oxygen dissociation curve?

Answer 4

harder for 4th O2 to bind, as low probability for O2 to find remaining binding site

Question 5

how does CO2 concentration affect affinity?

Answer 5

higher CO2 decreases affinity (Bohr effect)

Question 6

how does pH affect affinity?

Answer 6

higher pH increases affinity

Question 7

different conditions and different haemoglobin molecules from different organisms give different dissociation curves. what does this prove?

Answer 7

evolution

Question 8

how does CO2 lower pH?

Answer 8

dissolves in plasma and therefore forms carbonic acid