1. The document discusses heme proteins such as hemoglobin and myoglobin. Hemoglobin transports oxygen in red blood cells, while myoglobin stores oxygen in muscle cells. 2. Both hemoglobin and myoglobin contain a heme group which binds oxygen. In hemoglobin, the binding of oxygen to one heme group facilitates binding to the other heme groups, known as cooperativity. 3. Environmental factors like pH and carbon dioxide concentration affect oxygen binding and release from hemoglobin, known as the Bohr effect. A lower pH or higher carbon dioxide leads to oxygen being more readily released from hemoglobin.

1. under the supervision of
Dr.YASSERAZIMASSISTANTPROFESSOR
DEPT.OFAPPLIEDCHEMISTRY,AMU
Yaseer.azim@gmail.com
ABUDARDA
Abudarda.ms@amu.ac.in
TEAMLEADERZHCET-AMU

2. Myoglobin
Oxygen transport by Hb
Hemoglobin
Oxygen binding site
Co- opretivity Effect
Bohr Effect
Royal Mirage
Heme Protein

3. Heme protein
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4. ABOUTHEME
1. Fe2+ + Protoporphyrin IX = HEME
2. Mb and Hb are “heme” proteins.
3. Bound to the protein permanently, either covalently or
noncovalently bound or both.
4. Porphyrins are colored.
– Iron porphyrin gives red color to blood.
– Magnesium porphyrin gives green color
to plants.
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5. STRUCTUREOF HEMEPROTIEN
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6. SYNTHESISOF HEME
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7. DEGRADATION OF HEME
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8. BIOLOGICALFUNCTIONSOF HEMEPROTIEN
• Oxygen transport & store –Mb,Hb
• Catalysis- peroxidases, cytochrome c oxidase
• Electron transfer- cytochrome a, cytochrome
b, cytochrome c.
• Defense- catalase.
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9. DISORDERS
• Porphyria
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10. hemoglobin
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11. • Hemoglobin is the basic metalloprotein that is present in
the red blood cells which are responsible for carrying
oxygen.
• Hb + 4O2 HbO8
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→
→

12. FUNCTION OF RBC
The main function of red blood cells-
 Transfer of O2 from lungs to tissues.
 Transfer of CO2 from tissues to lungs.
Each red blood cells has 640 million molecules
of Hb
Haemoglobin protien constituting 1/3 of the red blood
cells.
 Molar mass of Hb-64500
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13. SYNTHESISOFHEMOGLOBIN(Hb)
Two Parts
Haem
Globin
HEAM
o PROSTHETIC GROUP
o CONTAINING Fe+2 ION
GLOBIN
o HEME CONTAINING PROTEINS
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14.  Hemoglobin is found exclusively in RBCs.
 Its main function is to transport oxygen from lungs to the tissues
& carbon dioxide & hydrogen protons from tissues to lungs.
 LUNGS TISSUES
Function of hemoglobin
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O2
CO2
→→

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 Tetramer complex
Contain four globin
molecules
Each globin contains 1
heme
Fe+2 ion in centre of heme
Fe+2 is known as
feroheme

16. Anaemia symptoms
Loss of energy
Leg cramps
Difficulty concentrating
Rapid heart beat
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17. o Seafood
o Eggs
o Dried fruits
o Fruits
o Chocolate
o Meat
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18. OXYGEN TRANSPORT BY
HAEMOGLOBIN
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19. Complex Protein containing HAEM (Iron)
1 molecule of Haem combines with 4 molecules of
Oxygen to form OXYHAEMOGLOBIN
Hb + 4O 2 → HbO8
Haemoglobin Oxygen Oxyhaemoglobin
The reaction is Reversible
→
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20.  At lungs there is low (carbon dioxide) so Hb has a
greater affinity for Oxygen- so picks up more
 Oxyhaemoglobin releases its oxygen where it is most
needed :to the actively respiring tissues
 At the Tissues there is high (carbon dioxide) this reduces
Hb affinity for oxygen so it gives it up
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21.  Oxygen dissociation curve of
Oxyhaemoglobin
 The curve shows that:
 at relatively low oxygen concentrations there is uncombined haemoglobin in
the blood and little or no oxyhaemoglobin, e.g. in body tissue
 at relatively high oxygen concentrations there is little or no uncombined
haemoglobin in the blood; it is in the form of oxyhaemoglobin, e.g. in the
lungs
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22. 1. Deoxygenated blood is transferred from
heart to lungs
2. CO2 in blood is exchanged for O2 in lungs
3. The oxygenated blood is then carried
by Haemoglobin from lungs to heart
4. Heart pumps out the oxygenated blood
to arteries towards tissues
5. This Oxygen in blood is exchanged for CO2 in
tissues
6. The deoxygenated blood is finally
transferred to heart
The Circulatory system
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23. ROYAL MIRAGE
myoglobin

24. History facts
• First protein to have its three-dimensional structure
• In 1958, John Kendrew and associates successfully
determined the structure of myoglobin by high-
resolution X-ray crystallography.
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25. WHAT IS MYOGLOBIN?
• Myoglobin is an iron- and oxygen-binding protein
found in the muscle tissue of vertebrates in general
and in almost all mammals.
• Molecular weight-16,700 Daltons.
• Number of residues- 153
• Number of Polypeptide Chains-1
• Myoglobin forms pigments responsible for making
meat red.
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26. Structure & functions:
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27. • Myoglobin (Mb) is a single-chain globular protein
of 153 or 154 amino acids.
• Containing a heme (iron-containing porphyrin)
prosthetic group in the center.
• It has eight alpha helices and a hydrophobic core.
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28. Functions:
• Stores oxygen in muscles.
• During starving condition it release oxygen to the
body tissues.
• Myoglobin forms pigments responsible for making
meat red.
• High concentrations of myoglobin in muscle cells
allow organisms to hold their breaths longer.
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29. Role in disease:
• Rhabdomyolysis
• Acute renal failure
• It is a sensitive marker for muscle injury.
• it is a potential marker for heart attack in patients
with chest pain.
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30. OXYGENBINDINGSITE
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31. WHAT IS OXYGEN BINDING?
• Binding of Oxygen ( O2) to Heme proteins i.e.,
haemoglobin, myoglobin & hemocyanin etc.
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32. HAEMOGLOBIN& MYOGLOBIN
• Haemoglobin & myoglobin are oxygen transporter and
storage proteins.
• Haemoglobin is tetrameric while Myoglobin is
monomeric.
• Hb: two α chains of 141 residues & two β chains of 146
residues.
• Hb: Molecular weight- 64,000 daltons.
• Mb: 153 amino acids, Molecular weight-17,700 daltons.
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34. • Fe in the heme group is the site for oxygen binding.
• Hb forms a reversible bond with the Oxygen.
• When Oxygen binds Ferrous state ( Fe+2) changes to
Ferric state (Fe +3).
• Single Hb unit can bind 4 Oxygen molecule.
• Binding of Oxygen with Hb is called cooperative
binding.
HOWOXYGENBINDSWITHHEMOGLOBIN?
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36. • Its binding is similar to hemoglobin.
• Fe in Mb is in ferrous state- that binds oxygen.
• Oxidation of Fe yields 3+ charge i.e., ferric state-
metmyoglobin does not bind oxygen.
• One Mb unit can bind only one Oxygen molecule.
• Its binding is called non-cooperative binding.
BINDINGOFOXYGENWITH
MYOGLOBIN
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37. • Hb undergoes a conformational changes on binding
Oxygen.
• Two major conformation of Hb-
R (relaxed) and T( tense) state.
• T- state is more stable (deoxyhemoglobin).
• Binding O2 to hemoglobin subunit in T-state triggers
a change in conformation to R-state.
CONFORMATIONAL CHANGES IN Hb
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38. ROYAL MIRAGE

39. • Heme group is non-planar in deoxygenated state.
• Oxygen binding pulls the Fe into the heme plane.
• Fe pulls its His F8 ligand along with it.
• In oxygenated state, heme group is planar.
• The F helix moves when oxygen binds.
• Total movement of Fe is 0.029 nm-0.29 Å.
GEOMETRICALCHANGES
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41. Cooperativity of Haemoglobin
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42. What is cooperativity effect?
 The phenomenon where the addition of oxygen to one Heme
group facilites its addition to the other Heme groups of
Haemoglobin is known as Cooperativity Effect
 The cooperativity of O2 binding to Haemoglobin influences
how much of the blood O2 is delivered to any particular
tissue
 This property is called an OXYGEN DISSOCIATION
CURVE
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43.  Shows the amount of O2 that is
bound to Haemoglobin (Y-axis)
as a function of partial pressure
of O2 in the blood plasma (X-
axis)
Because of the cooperativity
this dissociation curve is
S-shaped.
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44. • Successive oxygenation reactions of haemoglobin are as follows:
Hb + O2 𝑯𝒃𝒐 𝟐
Hbo2 + O2 Hb(O2)2
Hb(O2)2 Hb(02)3
Hb(O2)3 + O2 Hb(O2)4
Overall rate constant
K =
[𝑯𝒃 𝑶 𝟐 𝟒
]
𝑯𝒃 𝟎 𝟐
𝒏 ; K = Binding constant & n = Hill constant
Value n=4 represents MAXIMUM COOPERATIVITY EFFECT
Binding constant of oxyhaemoglobin
K1
K2
K3
K4
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→
→
→
→→
→
→
→

45. Explanation of Cooperativity Effect
 In deoxyhaemoglobin,the heme group is out of the plane and
iron is in +2 oxidation state and in high spin
 Oxygen binds to the heme group through vacant sixth
coordination site and iron is in +3 oxidation state and in
low spin
 These changes in the heme unit due to its coordination with
O2 trigger the cooperativity phenomenon
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46. Bohr effect
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47. About Christian Bohr
Christian Harald Lauritz Peter Emil Bohr
• 1880 MS from
University of Leipzig
•1886 Prof. university
of Copenhagen
•1891 Dead space
•1903 Bohr effect
•Danish physiologist
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48. •The effect of pH and CO2
concentration on the binding and
release of oxygen by hemoglobin
•Lowering the pH
•Raising the partial pressure of co2
•The release of O2 from oxyhemoglobin
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BOHR EFFECT

49. Fractionalsaturation
Oxygen partial pressure
At lower pH, His 146 is
protonated which favours
the deoxyHB
conformation thereby
leading to release of O2
Carbamate ROYAL MIRAGE

50. O2
O2
O2O2
O2
O2O2
O2
Raising partial pressure of carbon dioxide
Lowering pH
Oxyhemoglobin Deoxyhemoglobin
Peripheral tissues
O2
2H+ + 2HCO3
- 2H2CO3
2CO2 + 2H2O
Carbonic
anhydrase
2CO2 + 2H2O
Exhaled
Carbonic anhydrase
2HCO3
- + 2H+
4O2
Lungs
2H2CO3
Hb + 4O2
Hb + 2H+
(buffer)
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52. ROYAL MIRAGE

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