Flashcards in Transport Of O₂ Deck (11):
carries 4 oxygen molecules
4 sub units
4 polypeptide chains
haem (non-protein) group in each = iron ion Fe²⁺
iron ion has high affinity (attraction to oxygen)
haemoglobin ___________ curve is _ shaped.
___ is plotted against ___
% saturation with O₂
use what key words when talking about haemoglobin and oxygen?
how is the concentration of oxygen measured?
by relative pressure it contributes to mixture of gases
this is the partial pressure of oxygen or pO₂ also called oxygen tension
What is the partial pressure of oxygen (pO₂)?
the relative pressure that it contributes to a mixture of gases
What is oxygen tension?
partial pressure of oxygen
What happens at low oxygen tension?
Haemoglobin doesn't readily associate with oxygen because the haem group is in the middle so oxygen molecules can't reach it. So there is a low saturation level of haemoglobin at low oxygen tensions.
What happens when oxygen tension rises?
The diffusion gradient into haemoglobin molecules increases.
When the first O₂ associates, a conformational change in haemoglobin occurs, then it easily allows more O₂ to bind. This causes the steepness of the curve as pO₂ rises.
What happens at high oxygen tension?
as approaches 100% saturation of haemoglobin, the curve levels off
_____ in lungs is _________, and ______ in ____ is _______ to _________
high to produce close to 100% saturation
cause oxygen to dissociate from oxyhaemoglobin