Haemoglobin
→
Haemoglobin 's role is to
transport oxygen
.
Haemoglobin has four Each
polypeptide
•
a
quaternary structure ,
in which all
polypeptide chains are linked together .
is
> + "
associated with haem Fe Each Fe combine with molecule
a
group ,
which contains a ion . ion can a
single oxygen
total of four single
( Oz ) ,
making a 0, molecules that can be carried by a haemoglobin .
form
In oxygen joins blood
in
the lungs to
haemoglobin red cells to
haemoglobin
•
•✗
.
,
turns back
Near the
body cells ,
oxygen leaves haemoglobin and it to
haemoglobin
-
☐✗ .
loading ( associating)
Hb 402 Hbos
'
+ ,
haemoglobin oxygen unloading oxy haemoglobin
(
dissociating)
Affinity of
Haemoglobin
for
→
Affinity oxygen means the tendency a molecule has to bind with
oxygen .
Haemoglobin changes its
affinity for under different conditions This is because its
shape changes in the
•
oxygen
.
of certain substances C02
presence ,
such as .
At of of
-
higher concentrations carbon dioxide , the new shape the
haemoglobin molecule binds more
loosely to
to hence
oxygen haemoglobin releases its
oxygen .
Region of Affinity of Result
po , poo ,
body haemoglobin for 02
Gas
exchange High Low High oxygen is
surface associated
Respiring ↳W High
Low oxygen is
tissues dissociated
Different Have Different Haemoglobin
Organisms
Each different
produces haemoglobin with
slightly primary hence different
tertiary &
•
species a a structure
quaternary
structure
leading to different
oxygen binding properties .
Depending its structure haemoglobin molecules from those that have high affinity for to those
-
on
range a
oxygen
for
that have a low
affinity oxygen .
Oxygen Dissociation Curves %
' " """"" " " " H e r r m a n n,
'
- , , , -
¥ ,
3
-
An dissociation curve shows how saturated the
oxygen
haemoglobin is with
oxygen at
any given partial pressure .
2
1 When
P02 is low ( At tissues )
-
At low concentrations little to
oxygen ,
oxygen binds
unloads
haemoglobin .
→
oxygen
Shape of the haemoglobin molecule makes it difficult for the
'
the first oxygen moecule to bind to one of the sites on its
four
polypeptide subunits because
they are
closely United .
→
Haemoglobin 's role is to
transport oxygen
.
Haemoglobin has four Each
polypeptide
•
a
quaternary structure ,
in which all
polypeptide chains are linked together .
is
> + "
associated with haem Fe Each Fe combine with molecule
a
group ,
which contains a ion . ion can a
single oxygen
total of four single
( Oz ) ,
making a 0, molecules that can be carried by a haemoglobin .
form
In oxygen joins blood
in
the lungs to
haemoglobin red cells to
haemoglobin
•
•✗
.
,
turns back
Near the
body cells ,
oxygen leaves haemoglobin and it to
haemoglobin
-
☐✗ .
loading ( associating)
Hb 402 Hbos
'
+ ,
haemoglobin oxygen unloading oxy haemoglobin
(
dissociating)
Affinity of
Haemoglobin
for
→
Affinity oxygen means the tendency a molecule has to bind with
oxygen .
Haemoglobin changes its
affinity for under different conditions This is because its
shape changes in the
•
oxygen
.
of certain substances C02
presence ,
such as .
At of of
-
higher concentrations carbon dioxide , the new shape the
haemoglobin molecule binds more
loosely to
to hence
oxygen haemoglobin releases its
oxygen .
Region of Affinity of Result
po , poo ,
body haemoglobin for 02
Gas
exchange High Low High oxygen is
surface associated
Respiring ↳W High
Low oxygen is
tissues dissociated
Different Have Different Haemoglobin
Organisms
Each different
produces haemoglobin with
slightly primary hence different
tertiary &
•
species a a structure
quaternary
structure
leading to different
oxygen binding properties .
Depending its structure haemoglobin molecules from those that have high affinity for to those
-
on
range a
oxygen
for
that have a low
affinity oxygen .
Oxygen Dissociation Curves %
' " """"" " " " H e r r m a n n,
'
- , , , -
¥ ,
3
-
An dissociation curve shows how saturated the
oxygen
haemoglobin is with
oxygen at
any given partial pressure .
2
1 When
P02 is low ( At tissues )
-
At low concentrations little to
oxygen ,
oxygen binds
unloads
haemoglobin .
→
oxygen
Shape of the haemoglobin molecule makes it difficult for the
'
the first oxygen moecule to bind to one of the sites on its
four
polypeptide subunits because
they are
closely United .
