Hb Test

Question 1

Describe co-operative binding

Answer 1

• After the first oxygen binds, the second one binds easier
• The first oxygen binding changes the quaternary strucutre of the hameoglobin, so it changes shape
• This uncovers another haem binding site for the second oxygen to bind to

Question 2

Describe and explain the level and type of protein comprising haemoglobin

Answer 2

• Globular (specific shape for binding)
• Quaternary
• 4 polypeptide chains, and 4 haem binding groups

Question 3

Describe and explain the process of oxygen loading to haemoglobin

Answer 3

• Occurs in lungs, where p(O2) is high
• Haemoglobin has a high affinity for oxygen
• Oxygen will load/associate with haemoglobin more readily
• Forming oxyhaemoglobin

Question 4

Describe and explain the process of oxygen unloading from haemoglobin

Answer 4

• Occurs at respiring tissues, where p(O2) is low
• As oxygen is required by respiring tissues for aerobic respiration, to release energy
• Haemoglobin has a low affinity for oxygen
• Oxygen will unload/dissociate with haemoglobin more readily
• Unloading is linked to a high concentration of carbon dioxide - Bohr effect

Question 5

Describe the red curve

Answer 5

• Foetal haemoglobin
• Oxygen transferred to foetus from mother at placenta
• Haemoglobin has a higher affinity for oxygen
• Oxygen will load/associate more readily with haemoglobin

Question 6

Describe the blue curve

Answer 6

• Haemoglobin for a smaller mammal
• Haemoglobin has a lower affinity for oxygen
• Oxygen unloads/dissociates more readily
• To supply respiring tissues with more oxygen for increased rate of aerobic respiration
• To release more energy