7.1& 7.2Haemoglobin and oxygen transport Flashcards
Haemoglobin
is what type of protein
Globular protein
Haemoglobin
found where
In red blood cells
Dissociation
The process where oxygen is released at the tissues from oxyhaemoglobin
Haemoglobin’s affinity
It has a high affinity (attraction) for oxygen
Formation of oxyhaemoglobin
red blood cells reach the lungs
oxygen diffuses into the red blood cells
binds to the haemoglobin
= oxyhaemoglobin
How many molecules of oxygen can bind to one haemoglobin molecule
four
What makes haemoglobin red?
iron ion
Haem group
what and where
prosthetic group in each polypeptide chain of the haemoglobin molecule
What does the haem group contain
an iron ion
What structure does haemoglobin have
quaternary structure with 4 different polypeptide chains
Formula for oxygen partial pressure
pO2
What is oxygen partial pressure
The concentration of oxygen in cells
Formula for carbon dioxide partial pressure
pCO2
What is pO2 important for
determining whether oxygen binds to haemoglobin (affinity)
High pO2 means
haemoglobin has a high affinity for oxygen and oxygen binds to haemoglobin
Low pO2 means
haemoglobin has a low affinity for oxygen and oxygen dissociates from haemoglobin
Animals at altitude
haemoglobin
has a high affinity for oxygen
as air at higher altitudes has a low partial pressure
High metabolic rate
haemoglobin
haemoglobin that dissociates oxygen easily
allows oxygen to be readily and easily supplied to cell for use in respiration
When the first molecule of oxygen binds to the haemoglobin…
conformational change occurs (change in shape of protein)
and it becomes easier for more oxygen molecules to bind
so % saturation increases quickly
As more oxygen molecules bind to haemoglobin…
it becomes more difficult for oxygen molecules to bind
so % saturation begins to plateau
Respiring cells partial pressures?
low pO2 and high pCO2
When pCO2 is high…
the rate of oxygen dissociation increases
The Bohr effect
the increased dissociation of oxygen causes a shift in the curve to the right
(means oxygen will dissociate at a lower pO2 than normal)
Organisms with a lower conc. of oxygen have haemoglobin…
with a higher affinity for oxygen
dissociation curve to the left
