Page 35 - The Miracle of Creation in DNA

1st strand is either
1st strand erroneous or damaged damaged region is
base pairs removed
2nd strand

sugar-phosphate
backbone
DNA polymerase enzyme Once the correct
nucleotide is incorporated,
identifies and inserts the
the resulting nicks in the
correct nucleotide. DNA are sealed by a DNA
ligase. Now the 1st strand
is repaired.
DNA repairs itself and permits no errors.
When the DNA synthesis is complete, an error occurs in one nucleotide in a thousand. Yet
such errors have been prepared for. There is a special group of enzymes charged with
repairing errors that occur during the DNA synthesis. These enzymes identify the error in a
conscious manner and remove the defective nucleotide. They synthetise a new nucleotide
and insert it back during the process.

The new DNA molecules that emerge during replication are checked
repeatedly by inspector enzymes. If any mistake is made-which can be
quite vital, it is immediately identified and corrected. The erroneous code
is removed and replaced by the correct one. Although all these processes
take place at such a dazzling speed-3,000 base pairs are produced in a
minute,-all these pairs are checked repeatedly by the enzymes in charge
and the necessary amendments are made.
The following facts, which are particularly revealing will give a
better understanding of the great speed at which DNA multiplies. The
division of one cell lasts between 20 and 80 minutes, and the information
on DNA needs to be copied and multiplied within that time scale. In other
words, the 3 billion pieces of information in DNA can be copied in
between 20 and 80 minutes with no faults or omissions. That is as
miraculous as the perfect reproduction in such a short space of time as all
the information in a library, or 1,000 books, or a million pages. And note
carefully, it is not technological equipment or advanced photocopiers that
do this, but enzymes formed by collections of atoms.

DNA: The Data Source of Life 33