The document discusses antibodies, specifically immunoglobulins, which are Y-shaped glycoproteins made of two heavy and two light peptide chains. It details the five types of antibodies (IgA, IgD, IgE, IgG, IgM) and their roles in immune response, highlighting that IgG is the most abundant and can cross the placenta, while IgA serves as the first line of defense. Additionally, it outlines the functions and characteristics of each antibody type, including their structure and areas of action within the body.

1. ANTIBODY
STRUCTURE AND TYPES

2. IMMUNOGLOBINS
Produced or formed by the body for self
defense against antigen or foreign
bodies.

3. STRUCTURE
Y – shaped glycoproteins . It contains two
heavy peptide chains and two light peptide
chains.
Also known as H2 L2

4. There are five
types of
antibodies
•Ig A
•Ig D
•Ig E
•Ig G
•Ig M

5. I g G
•Most abundant
antibody in the body .
• Provides protection
against viral and
bacterial infections by
enhancing
phagocytosis .
•Provides long term
resistance against
diseases.
•Only antibody that can
cross the placenta
from mother to child .

6. Ig A
•It’s the second most
abundant antibodies in
the body.
•It is mainly found in
sweat , saliva , tears ,urine
•It provides the first line of
defence against inhaled
and ingested pathogens
and fights against
pathogens even before a
person is sensitised.

7. I g M
•Largest
immunoglobin
molecule.
•When B-
lymphocytes are
stimulated this
antibody appears
first; and produces
primary antibody
response.

8. I g E
• It’s mainly concentrated
in mucous membranes ,
skin and lungs .
• It triggers
hypersensitive reactions
by inducing basophils
and mast cells to release
histamine.
• It is involved in allergic
reactions and also
provides protection
against parasitic worms.

9. Ig D
• It is mainly found
on the surfaces of
the B-cells as
antigen receptors.
• Here it activates
B-cells for antigen
recognition.
• It occurs in very
small amounts in
blood serum.