7.2 Transport of oxygen by haemoglobin

Question 1

What is the explanation for oxygen dissociation curves

Answer 1

1. The shape of the haemoglobin molecule makes it difficult for the first oxygen molecule to bind. This is because the sites are closely united
2. The binding of the first oxygen molecule changes its quarternary structure and makes it physically easier for other subunits to bind to an oxygen molecule
3. After the binding of the third molecule it is harder because the majority of binding sites have been occupied, and it is unlikely that a molecule will bind to this one unoccupied site in terms of probability

Question 2

What does a curve further to the left mean

Answer 2

There is a greater affinity for oxygen

Question 3

What does a curve further to the right mean

Answer 3

There is less affinity for oxygen