Page 38 - The Miracle of the Immune System

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THE MIRACLE OF THE IMMUNE SYSTEM

1,920,000 different antibodies are formed as a result of 5,200 different
combinations. This process represents a wisdom and planning that are
4
too great for the human mind to comprehend, let alone design.
An unlimited number of combinations can be made with the use of
one hundred thousand genes. The cell, however, uses, with great intelli-
gence, only 5,200 basic combinations and produces 1,920,000 specific an-
tibodies. How has the cell learned to make the right combinations out of
these unlimited possibilities to form the required antibodies?
Making the correct combinations out of an infinite number of possi-
bilities aside, how has the cell got this idea of making combinations?
Moreover, the produced combinations serve a certain purpose, and

An individual B cell makes copies of its own specific antibody
and attaches them to the outer surface of its cell membrane. The
antibodies extend outward like minute, highly tuned aerials wait-
ing for contact with the specific bit of protein that they can
recognize. An antibody is made of two light and two
heavy chains of amino acids held together in a Y
shape. The constant regions of chains are the same
in many different types of antibodies. But the
variable regions - the tips of the arms -
each have a uniquely shaped cavity
that fits exactly onto the shape Variable region
of the antibody's "cho- of light chain
Variable region
sen" protein frag-
Contant region of of heavy chain
ment.
light chain
Antibodies Constant region
of heavy chain

Carbohydrate group

Antigen-binding site
B cell