Organisms Exchange Substances with their Environment: Mass Transport in Animals - Other Types of Haemoglobin

Question 1

What factors may affect the type of haemoglobin an organism has?

Answer 1

• Where they live (low/hig oxygen concentration)
• How active they are
• Their size

Question 2

What is haemoglobin like for organisms living in low oxygen environments?

Answer 2

• Haemoglobin has a higher affinity for oxygen than human haemoglobin
• Not much oxygen available, so haemoglobin has to be very good at loading available oxygen
• Oxygen dissociation curve is to the left of ours
• E.g lugworm

Question 3

What is haemoglobin like for active organisms?

Answer 3

• Active organisms have a high oxygen demand so have haemoglobin with a lower affinity for oxygen than human haemoglobin
• Haemoglobin needs to easily unload oxygen, so it’s available to use
• Oxygen dissociation curve is to the right of ours
• E.g hawk

Question 4

What is haemoglobin like for small mammals?

Answer 4

• Small mammals have a high SA:V
• They lose heat quickly, so they have a high metabolic rate to keep them warm - which requires a lot of oxygen
• They have a lower affinity for oxygen than human haemoglobin, to meet high oxygen demands
• Oxygen dissociation curve is to the right of ours
• E.g rat

Question 5

What is foetal haemoglobin like?

Answer 5

• Has a higher affinity for oxygen compared to adult haemoglobin
• Needs to be better at absorbing oxygen because by the time oxygen reaches placenta, oxygen saturation of blood has decreased

Question 6

What is myoglobin?

Answer 6

• Myoglobin act as oxygen storage molecule that only releases oxygen when pO2 is extremely low​
• Good for organisms that travel between areas of high and low oxygen concentrations e.g marine animals
• Found in muscle tissue