Hemoglobin Definition Structure Types of Hemoglobin

1. Nimra Faraz
DPT
HEMOGLOBIN

2. DEFINITION
 Hemoglobin is the IRON containing PROTEIN compound
within red blood cells that carries OXYGEN throughout the
body .
 STRUTURE
 Hemoglobin is a large protein molecule folded around
four iron atoms and it has a quaternary structure . A
quaternary structure is where two or more polypeptide
chains join could be ionic , covalent or hydrogen bonds
.
 In hemoglobin there are four polypeptide chains , each
one of these polypeptide chains contains a heme
group which is able to bind to one oxygen molecules
.therefore four oxygen molecules can transported by
each hemoglobin molecule .
 In every red blood cell there are approximately 270
million hemoglobin molecules and so each red blood
cell can carry about 1080 million oxygen molecules .

3. Structure of hemoglobin

4. HEME MOLECULE

5. TYPES OF HEMOGLOBIN
 There are Seven types of hemoglobin molecules througout a
human’s life , four when you are an embryo , One once you
develop into a fetus and then as an adult you have two .
 EMRYONIC HEMOGLOIN
 The form of hemoglobin most common and highest in
proportion in an embryo is Hemoglobin Gower I. The
four polypeptide chains that compose this type of
hemoglobin are two Zeta and two Epsilon chains.
The other three hemoglobin are present at much lower
level :
 Hemoglobin Gower II composed of two Alpha and two
Epsilon chains .
 Hemoglobin Portland I comprised of two Zeta and two
Gamma polypeptides.
 Hemoglobin portaland II made of Zeta and two Beta
polypeptide chains .

6. FETAL HEMOGLOBIN
 Once the embryo develops into fetus and the four
types of embryonic hemoglobin molecules
disappear they are replaced by hemoglobin F.
 This type of hemoglobin is used due to it having a
great affinity for oxygen than adult hemoglobin
.therefore the growing fetus is able to take its
mother’s oxygen which is in her bloodstream .
ADULT HEMOGLOBIN
 Hemoglobin F remain in child’s blood until it is
around six months old and then almost all of it
replaced with adult hemoglobin

7. •Hemoglobin A: it has two Alpha chains and two Beta
chains .
 Hemoglobin A2 : it has two Alpha polypeptides
and two Delta polypeptides.
 Hemoglobin A is most prevalent as it makes up
about 97% of adult hemoglobin .

8. HEMOGLOBIN SYNTHESIS
 Hemoglobin synthesis requires the coordinated
production of Heme and Globin . Heme is
prosthetic group that mediates reversible binding
of Oxygen by Hemoglobin . Globin is the protein
that surrounds and protects the heme molecules .
ROLE OF HEMOGLOBIN
 The role of hemoglobin is rather similar to a
delivery truck driver . The is because hemoglobin
loads oxygen , transports oxygen and then finally
unloads it .
 the process by which hemoglobin loads oxygen is
called associating , and this occurs in region of
high oxygen concentration – the lungs . Here the
oxygen and hemoglobin combine forming
oxyhemoglobin .

9. •The process in which hemoglobin unloads oxygen is
called disassociating and occurs in regions of low
oxygen concentration – in tissues.
 Here oxyhemoglobin splits back into oxygen and
hemoglobin
 Oxygen + Hemoglobin
Oxyhemoglobin

10. THANK YOU !