Heamoglobin Flashcards
what type of protein is heamoglobin and why?
qauternary -has 4 polypetide chain
give the equation for oxygen loading
Hb+4O2->HbO8
haemoglobin +oxygen -> oxyheamoglobin
give the equation for oxygen unloading
HbO8->4O2+Hb
oxyhaemoglobin ->oxygen +haemoglobin
where is oxygen loaded ?
lungs
where is oxygen unloaded
respiring cells
what is affinity?
ability of a molecule to bind to something
what is the symbol for partial pressure of oxygen?
PO2
what does higher PO2 mean?
greater concentration of dissolved oxygen in cells
as PO2 increases…
haemoglobin affinity for oxygen also increases
what ‘letter’ shape is a haemoglobin dissociation curve?why does this matter?
‘S’ shape , not linear
what is on the Y and X axis of the curve ?
X axis is partial pressure of O2 /KPa
Y axis is % saturation of haemoglobin with oxygen
what happens at the start of the graph ?
when PO2 is low haemoglobin has a low affinity for O2 ,so a low saturation if O2 .
what happens at the top of the graph ?
When PO2 is high in the lungs ,haemoglobin has a a high affinity for O2 so it has a high saturation of O2
why is the haemoglobin dissociation curve s shaped?
saturation affects affinity .When haemoglobin binds with the first O2 molecule ,3d shape of haemoglobin changes , The altered shape means it is easier for 2nd O2 molecule to bind .As haemoglobin becomes more saturated it becomes harder for O2 to bind .
what is PCO2?
partial pressure of CO2
what effect does PCO2 have on oxygen unloading #?
Hb gives up O2 more readily at a higher PCO2 .More O2 to cells during same affinity .CO2 makes blood more acidic which changes the hap of the protein haemoglobin
describe the steps of the Bohr effect?
1.cells respire and produce more CO2 which raises PCO2
2.decrease in Ph
3.increased rate of O2 unloading
4.dissosiation curve shifts tot the right
5.Hb affinity is decreased so more O2 relesead
what heamoglobin type do organisms with a low oxygen avalibility have and why?
higher affinity for oxygen then human Hb
not as much oxygen avalible so heamoglobin is very good at loading and unloadinh
what type fo oxygen dissosiation curve do organisms with a low oxygen avalibiltiy have ?
to left
what type of oxygen dissosiation curve do organisms with a high activity level have and why ?
Hb has lower affinity
Hb unload easier , avalible to use
oxygen to right due to high respiration level
what type of oxygen dissociation curve do organisms with a high SA:V have and why ?
lose heat quick so high metabolism to keep heat working well
high oxygen demand
Hb has a lower affinity for O2 as Hb needs to easily unload O2
move to right
