Haemoglobin & Oxygen Transport: In Depth: (Ms.D)

Question 1

How is OXYHAEMOGLOBIN formed?

Answer 1

-In the LUNGS O2 diffuse from ALVEOLI, into CAPILLARIES and into RBC
-O2 ASSOCIATES (binds) with HAEMOGLOBIN in RBC and forms OXYHGB
*Reversible reaction as O2 at respiring cells dissociated and back –> HGB

Question 2

How does the body ensure that O2 is BINDED/NOT where needed?

Answer 2

-HGB has HIGHER AFFINITY for O2 in O2 rich areas where the pO2 is high, promoting O2 LOADING
-HGB has a LOWER AFFINITY for O2 in O2 starved area where pO2 is low, promoting O2 UNLOADING

Question 3

How does the SATURATION of HGB AFFECT its AFFINITY for O2?

Answer 3

-As the sat. increases it makes it harder for the FINAL O2 MOLECULE to bind
-Meaning the sat. of HGB with increasing pO2 is NOT LINEAR

Question 4

Explain CO-OPERATIVE BINDING

Answer 4

-As each O2 BINDS onto the HGB, it changes the SHAPE of the structure
-The way in which it changes makes it easier for the further O2 molecules to BIND

Question 5

How does the partial pressure of CO2 affect HGBs AFFINTY for O2?

Answer 5

-When pCO2 Inc., the AFFINITY Decr.
-Due CO2 reacting with H2O to form H2CO3 (Carbonic Acid)
-Which causes the TERTIARY structure of HGB to be altered
-Also allows for EASIER DISSOCIATION of O2 (BOHR EFFECT)

Question 6

Why do FOETAL HGB need to have a HIGHER AFFINTY for O2?

Answer 6

-Need to steal O2 away from MUMS HGB
-Whilst they are in PLACENTA

Question 7

Describe ‘Mountain Dwellers’ HGBs AFFINITY for O2 (Low O2 Environment)

Answer 7

-As less O2 is delivered, the AFFINITY is HIGHER for O2
-The HGB has to be able to LOAD MORE O2 at LOWER pO2
-To ensure enough O2 is ABSORBED

Question 8

Describe HGBs AFFINITY for O2 in ORGANISMS with a SMALLER SA:V or with HIGH METABOLIC RATE

Answer 8

-AFFINITY DECREASES
-Has HIGH METABOLISM so it needs O2 to be RELEASED READILY

Question 9

How does INCREASED RESPIRATION affect BLOOD pH?

Answer 9

-Inc. pH
-Less CO2 so less CARBONIC ACID is CREATED