Haemoglobin

Question 1

How are red blood cells adapted for their function?

Answer 1

• Biconcave disc to increase surface area for oxygen transport
• No nucleus so more oxygen can be packaged in each RBC
• Lack of mitochondria to prevent use for respiration
• Advantage of nucleated RBC: can undergo mitosis

Question 2

What is haemoglobin?

Answer 2

• Functional and globular protein: quaternary structure
• 4 polypeptide chains: 2 alpha, 2 beta
• Each chain has a haem group with an iron iron
• At alveoli: oxygen + haemoglobin = oxyhaemoglobin