7.2 transport of oxygen by haemoglobin

Question 1

what would happen to the oxygen dissociation curve if the carbon dioxide concentration is high?

Answer 1

curve shifts to the right

Question 2

what would happen to the oxygen dissociation curve if the carbon dioxide concentration is low?

Answer 2

curve shifts to the left

Question 3

a rise in temperature shifts the oxygen dissociation curve to the right. suggest how this enables an exercising muscle to work more efficiently

Answer 3

• exercising muscle release heat, shifting the cure to the right
• causing haemoglobin to release more energy to fuel the muscular activity

Question 4

haemoglobin usually loads oxygen less readily when the concentration of carbon dioxide is high (the Bohr effect). the haemoglobin of lugworms does not exhibit this effect. explain why to do so could be harmful

Answer 4

• respiration produces carbon dioxide
• builds up when tide is out
• if exhibited Bohr effect, it would not be able to absorb oxygen when it was present in only very low concentrations in the burrow

Question 5

in terms of obtaining oxygen, suggest a reason why lugworms are not found higher up the shoreline

Answer 5

• higher part of the beach is uncovered by the tide fir a much longer period of time than the lower part
• during this longer period all the oxygen in the burrow would be used up and the lungworm might die before the next tide brings in a new supply of oxygen