Haemoglobin

Question 1

Define haemoglibon

Answer 1

Haemoglibon is a protein with a quaternary structure (made from 4 polypeptide chains)

Question 2

What has each polypeptide chain within a haemoglobin got?

Answer 2

Each one has a haem group, containing an iron ion

Question 3

How many oxygen molecules can haemoglobin carry?

Answer 3

4 oxygen molecules

Question 4

Haemoglobin has a high ——- for oxygen and can carry 4 oxygen molecules

Answer 4

Affinity

Question 5

Describe the reversible reaction for haemoglobin

Answer 5

• In the lungs, oxygen associates with haemoglobin forming oxyhaemoglobin
• when oxygen dissociates at the exchange tissues/body cells, haemoglobin is left on its own

Question 6

What does haemoglobin saturation depend on?

Answer 6

It depends on the partial pressure of oxygen

Question 7

What is partial pressure of oxygen?

Answer 7

The measure of oxygen concentration

Question 8

Describe the Bohr effect

Answer 8

• the idea that CO2 pressure affects the affinity of oxygen
• when there’s more CO2 the curve moves to the right and decreases the oxygen affinity, this shows there is respiration occurring

Question 9

What does a dissociation curve show?

Answer 9

How saturated haemoglobin is with oxygen at any given partial pressure

Question 10

Describe the trend if a dissociation valve move to the left?

Answer 10

It means that there is a higher affinity, as the organisms needs to pick up oxygen easier i.e at high altitudes

Question 11

Give an example where there is high saturation of haemoglobin (at the top of the curve)

Answer 11

The lungs

Question 12

Why will there be low saturation at the bottom of the dissociation curve?

Answer 12

As there is respiration happening