Respiration 3 Flashcards
What is Dalton’s law
The total pressure of gases is the sum of their individual partial pressures
What is the equation for conc of gas in a solution? (Henry’s law)
Gas = s x Pgas
s = solubility coefficient
P = partial pressure of the gas
Why is haemoglobin required?
Plasma cant deliver enough O2 (15ml O2/min whereas the body requires 250ml O2/min)
What is the structure of haemoglobin?
Tetrameric, porphyrin ring containing a single iron
Haem unit and globin chain
In adults : 2 alpha and 2 beta chains
In child : 2 gamma and 2 alpha chains
Where does oxygen bind in haemoglobin?
The Fe2+
What converts Fe3+ to Fe2+ in haemoglobin?
Methaemoglobin reductase
What 2 states does haemoglobin live in?
Tense (low affinity for O2)
Relaxed (high affinity for O2)
What effect does temperature have on haemoglobin?
As temp increases, the haemoglobin carries less oxygen
What is Bohr effect?
As the pH decreases, less O2 is carried by haemoglobin
What factors cause a right shift in a dissociation curve?
Increased temperature
Increased CO2 production
Decrease in pH
What is the result of decreased affinity for O2 on haemoglobin?
More O2 is released to the tissues
How does fetal haemoglobin differ to adult haemoglobin?
Gamma chains and alpha chains
Different sensitivity to 2, 3 DPG causing a left shift in the curve
How is CO2 transported by the blood?
CO2 is carried as dissolive carbon dioxide:
Carbonic acid (H2CO3)
Bicarbonate (HCO3-)
Carbonate
Carbamino compounds
What are the fates of CO2 in red blood cells?
4% remains dissolved in cytoplasm
Some binds to aa on haemoglobin protein
Majority is converted to Bicarbonate via carbonic anhydrase
What happens to Bicarbonate in RBC?
Transported out of RBC via an exchange with chloride
