How DNA Copies Itself
Using computer animation based on the latest research, we are now able to see how DNA is actually copied in living cells.
You are looking at an assembly line of amazing miniature biochemical machines that are pulling apart a DNA double helix and cranking out a copy of each strand. The DNA to be copied enters the production line from bottom left. The blue molecular machine is called helicase. It spins the DNA as at as a jet engine as it unwinds the double helix into two strands. One strand is copied continuously an can be seen splitting off to the right. Things are not so simple for the other strands because it must be copied backwards. It is drawn out repeatedly in loops and copied one section at a time. The end result is two new DNA molecules.
Similar to copying information on the computer, hundreds of megabyte data can be backed up in minute by burning a copy unto a cd. The copy in process is accurate typically one mistake in a billion.
The DNA copy process in our body is even more accurate – a thousand times better than most computers. Remarkable biochemical systems have evolved to double check the new DNA strands and fix any mistakes.
