Haemoglobin

Question 1

State the molecule that transports oxygen around the body

Answer 1

haemoglobin

Question 2

Describe the quaternary structure of haemoglobin

Answer 2

four polypeptides each with a heam group (containing iron) attached

Question 3

What is association/loading in relation to oxygen?

Answer 3

when oxygen binds to haemoglobin

Question 4

What is dissociation/unloading in relation to oxygen?

Answer 4

when oxygen is released from haemoglobin

Question 5

Explain what we mean by a ‘high affinity’ for oxygen

Answer 5

haemoglobin that takes up oxygen more readily but releases it less readily

Question 6

Explain what we mean by a ‘low affinity’ for oxygen

Answer 6

haemoglobin that takes up oxygen less readily but releases it more readily

Question 7

Explain why haemoglobin needs to change its affinity for oxygen

Answer 7

it must have a high affinity at the gas exchange surface and a low affinity at the respiring tissues

Question 8

How does the presence of carbon dioxide cause the affinity of haemoglobin to for oxygen to decrease?

Answer 8

carbon dioxide causes the shape of the heamoglobin to change

Question 9

Explain why haemoglobin from different animals has different affinities for oxygen

Answer 9

each species has a different amino acid sequence, therefore different tertiary and quaternary structure and so differrent oxygen binding properties