Page 74 - The Miracle of the Immune System

Bacteria
Bacteria

Antigen

Antibody A is
manufactured in Antibody B is
order to fit antigen A manufactured
in order to fit
antigen B

The anti antibody in the blood

The anti antibody in the blood

antibody binds to antigen on the
surface of the bacteria and renders it ineffective.
Antibody B would not
fit antigen A

Bacteria and viruses carry
Antibodies with different antigens
chemicals on their surfaces
cannot be effective against bacteria.
called antigens. Some lympho-
cytes produce antibodies to
bind themselves to antigens,
thus enabling the white cell to
easily ingest the bacteria.
Antibodies have distinct fea-
tures and they only bind to anti-
gens for which they are pro-
duced. As illustrated in the
Antibody A would not
above picture, a triangular anti- fit antigen B
gen perfectly fits to an anti-
body, which has a triangular
cut. (top left). Yet the same an-
tibody (bottom) does not fit to
a round antigen.