Haemoglobin

Question 1

What is the structure and function of haemoglobin?

Answer 1

STRUCTURE
-Quaternarny protein structure containing 4 polypeptides each with a haem group (Fe2+)
-Chemically similar molecules

FUNCTION
-Readily associate with oxygen
-Readily dissociate from oxygen at tissues requiring it

Question 2

What are the differences between haemoglobins in different organisms?

Answer 2

-Different shapes
-Slightly different amino acid sequence
-Therefore has a slightly different tertiary and quaternary structure
-This structure causes each haemoglobin to have a slightly different affinity for oxygen

Question 3

What is meant by loading and unloading of oxygen?

Answer 3

Loading (Associating) is when oxygen binds with the haemoglobin, taking place in the lungs in humans.

Unloading (Dissociating) is when oxygen releases from the haemoglobin, taking place in respiring tissues in humans.