Haemoglobin

Question 1

Describe the advantage of the Bohr effect during intense exercise

2 marks

Answer 1

1. Increases dissociation of oxygen;
   Accept unloading/ release/reduced affinity for dissociation
2. For aerobic respiration at the tissues/muscles/cells
   OR
   Anaerobic respiration delayed at the tissues/muscles/cells
   OR
   Less lactate at the tissues/muscles/cells;

Question 2

Describe and explain the effect of increasing carbon dioxide concentration on the dissociation of oxyhemoglobin

2 marks

Answer 2

1. Increases/more oxygen dissociation/unloading
   Deceases haemoglobin’s affinity for Oz;
   Accept more readily
   Accept releases more 02
2. (By) decreasing (blood) pH/increasing acidity;
   Reject if reference made to active site

Question 3

Use info in graph to explain how seal myoglobin ( oxygen carrying protein found in muscles ) dissection curve shows seal is adapted to diving

It shows curve has shifted left

2 marks

Answer 3

1. Higher affinity for oxygen (than HB)
   Dissociates oxygen less readily
   OR
   Associates more readily;
   Accept holds 02 at lower ppO
2. Allows (aerobic) respiration when diving/at low(er) pOz

Provides oxygen when haemoglobin unloaded

Delays anaerobic respiration/lactate production;
Accept acts as an oxygen store

Question 4

What do the link dissociation curves and unloading/ loading with?

Answer 4

Aerobic / anaerobic respiration

Question 5

Binding molecules of one molecule of oxygen to haemoglobin makes it easier for second oxygen molecule to bind

Explain why

2 marks

Answer 5

1. Binding of first oxygen changes tertiary / quaternary (structure) of haemoglobin;
   Accept conformational shift caused
2. Creates / leads to / uncovers second / another binding site
   OR
   Uncovers another iron / Fe / haem group to bind to;

Question 6

If haemoglobin formed by condensation reaction?

Yes or no

Answer 6

Yes