The DNA Alphabet
The DNA in the cell nucleus has a spiral structure. When this is opened
out, DNA turns into a long, thin string a metre or so in length. The way
that a metre or so of DNA is squeezed into a minute cell nucleus is a
subject requiring further consideration.
The atoms making up DNA have a superior design allowing the maximum amount
of information to be carried in the smallest possible area. Three elements
are found at every step of the two spiral ladders that twist around each
other: sugar, phosphate and hydrogen-containing organic bases that make
up the DNA codes. Although the tools and functions are the same in every
human being, the particular codes that allow people to be different from
one another are made up of these hydrogen bases. The differences in the
way these four different bases are set out are the reason for all the
differences between people. These bases are called Adenine, Guanine, Cytosine,
and Thymine. They are linked to each other according to specific rules.
Like a foreign language that scientists are just beginning to learn to
read, these four types of hydrogen-based organic bases conceal the entire
code of our biological existence.
These bases that make up the DNA molecule are known by their initial
letters, A, T, G and C. The information in the data bank in the cell nucleus
is stored in this way in an alphabet consisting of these four letters.
Each gene, which comprises one portion of the DNA molecule, determines
a particular feature of the human body. Countless properties like height,
eye colour, the material and the shape of the nose, ear, and skull are
formed by the command of the related genes. We can compare every one of
these genes to the pages of a book. On the pages there are scripts made
up of the letters A - T - G - C.
There are approximately 200,000 genes in the DNA of a human cell. Every
gene is composed of a special sequence of nucleotides, the number of which
ranges between 1000 and 186,000 according to the type of the protein it
correlates. These genes hold the codes of nearly 200,000 proteins that
function in the human body and control the production of these proteins.