Question

CHOOSE ALL THAT APPLY FOR 14) and 23). Thank you so mych!!

to a Question 14 2 pts Choose all that favor UNLOADING of oxygen from Hemoglobin. higher partial pressure of Carbon Dioxide lower pH lower partial pressure of CO2 higher pH

Answer 1

1.ANSWER - Higher partial pressure of carbon dioxide and lower pH.

OXYGEN TRANSPORT ;

• RBCs have a red Coloured iron containing pigment called haemoglobin.
• Oxygen binds with haemoglobin in a reversible manner to form oxyhaemoglobin.
• Each haemoglobin can carry 4 molecules of oxygen.
• This binding of oxygen mainly depends on partial pressure of oxygen.
• partial pressure of carbon dioxide,hydrogen ion concentration,temperature etc.are the other factors that influence this binding.
• On plotting percentage saturation of haemoglobin with partial pressure of oxygen we get the following curve called oxygen dissociation curve which is a sigmoid shaped curve ;

100 Percentage saturation of blood with oxygen 0 0 2 4 6 8 10 12 PARTIAL PRESSURE OF OXYGEN (PO2)

• This curve is used for studying the factors affecting the oxygen binding with haemoglobin like pCO2 ,H+ concentration etc.
• In alveoli - the conditions existing are - High pO2,low pCO2,lesser H+ concentration (high  pH) and low temperature - all these factors favors the formation of oxyhaemoglobin.
• In tissues - low pO2,High pCO2,higher H+ concentration( Low pH) and High temperature are the conditions; which favors and leads to the dissociation of oxygen from the oxyhaemoglobin.
• from the above analyzed conditions we can conclude that oxygen binds to haemoglobin in the lung surface and gets dissociated in the tissues.
• 
  100 90 80- Left shift (increased affinity) Lower CO, Higher pH Lower temperature 70 60 Hemoglobin saturation (%) 50 40 Right shift (reduced affinity) Higher CO, Lower pH Higher temperature 30 - 201 10 10 20 80 90 100 30 40 50 60 70 Oxygen partial pressure (mmHg)
  

2.Answer - Convert carbon dioxide and water to carbonic acid,help move carbon dioxide into and out of the cell.

• carbon dioxide is carried by haemoglobin as carbamino haemoglobin( about 20 -25 percent).This binding depends on the partial pressure of CO2 and partial pressure of oxygen .
• In tissues pCO2 will be high and pO2 will be less,which favors the binding of carbon dioxide with haemoglobin .
• In alveoli pCO2 will be low and pO2 will be high,resulting in the dissociation of carbon dioxide from carbaminohemoglobin ,so carbon dioxide who got bound to haemoglobin at tissues is delivered at the alveoli.
• RBCs contain a very high concentration of an enzyme called carbonic anhydrase and minute quantities present in plasma also.This enzyme catalyzes the following reactions ;

Carbonic anhydrase Carbonic anhydrase CO, +H,0 ZH,CO, HCO3 + H+

• At tissues ; pCO2 is high due to catabolism,CO2 diffuses into blood(RBCs and plasma) and forms bicarbonate and hydrogen ions.
• At alveoli; pCO2 is low,the above said reaction proceeds in opposite direction leading to formation of carbon dioxide and water.
• Thus carbon dioxide trapped as bicarbonate at the tissue level and transported to the alveoli is released out as carbon dioxide.