module 3: Haemoglobin Flashcards
what is it
globular protein with quaternary structure
4 polypeptide chains
each has team group containing iron
has a high affinity for oxygen
each molecule carries 4 o2\
oxygen going to iron to form oxyhaemoglobin
when is there a high partial pressure of oxygen
high concentration of sidles oxygen in cells
at a high po2
oxygen loads onto haemoglobin, has a high affinity for oxygen
at a low po2
oxyhemoglobin unloads oxygen, has a low affinity for oxygen
where is o2 unloaded
repairing tissues where there is a low po2
where is there a high po2
alveoli
what does a dissociation curve show
ow saturated the haemoglobin is with oxygen at any partial pressure
why is a dissociation curve ‘s’ shaped
when Hb combines with the first o2 molecule, its shape alters to make it easier for other o2 to join, as Hb becomes saturated its harder for o2 to join
fetal haemoglobin
has a higher affinity for o2 than adult at the same po2
why does FH have a higher affinity
gets o2 from mother across placenta
by the time mothers blood reaches placenta it has passed cells so oxygen saturation has decreased
how does co2 affect oxygen unloading
Hb gives up o2 more readily at a higher pCO2 so more oxygen gets to cells during activity
higher pco2 during respiration
what happens when co2 diffuses into red blood cells
reacts with water to form carbonic acid catalysed by carbonic anhydrase
the carbonic acid splits into H+ ions and hydrodrogencarbonate ions
what does the increase in h+ ions cause
oxyhb to unload o2 so Hb can load the ions forming haemoglobinic acid
what does the increase in h+ ions cause
oxyhb to unload o2 so Hb can load the ions forming haemoglobinic acid
what happens to HCO-3 ions
diffuse into blood plasma out now red blood cells causing chloride ions to diffuse into red blood cells, this is the chloride shift
