Haemoglobin and the Oxygen Dissociation Curve

Question 1

How are red blood cells adapted for transporting oxygen?

Answer 1

= bioconcave structure
= surface area to volume ratio- large
= has many haemoglobin
= does not have a nucleus- more volume for haemoglobin

Question 2

What is the structure of haemoglobin?

Answer 2

= globular protein
= 4 polypeptide chains
= each is bounded to a proesthetic group- haem (conjugated protein)- fe2+ ion, each fe2+ groups can bind with one oxygen
= 4 haem groups: 1 molecule 4 oxygen

Question 3

What is the name given to haemoglobin when it binds to oxygen?

Answer 3

= oxyhaemoglobin

Question 4

What is an oxygen dissociation curve?

Answer 4

= measure the amount of oxygen that combinds with haemoglobin
y: % saturation of haemoglobin with oxygen
X: partial pressure of oxgen (Kpa)
= S shapes curve
=

Question 5

What does the curve tell us?

Answer 5

= at around 4kpa of oxygen achieved 25% saturation
= each haemoglobin molecule binds to 1 oxygen molecule on average- low partial pressure of oxygen there is a low affinty for oxygen- “affinity” how strongly bounded to the oxygen
= once one oxygen molecule binds the affinity for oxygen increases- ewasier to bind firther oxygen molecules