David Oppertshauser
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    Today’s Food for Thought comes is an excerpt from an article by Jonathan Sarfati on the CMI website. Read it through then ask yourself: “Could all of this just happen by itself?”

 

We All living creatures contain incredible machines, as well as the ‘instruction manual’ to build them. This manual comprises sequences of chemical ‘letters’ (nucleotides) in the famous deoxyribonucleic acid (DNA) molecule, just as information in a book is written in letters on a page. DNA’s physical dimensions pose many problems that would need to be solved before even the simplest life could function. Furthermore, these instructions are copied to the next generation. You didn’t really get your mother’s eyes and father’s ears; rather, it was the instructions to re-manufacture your mother’s eyes and father’s ears that were copied to your DNA. DNA’s physical dimensions pose many problems that would need to be solved before even the simplest life could function. The double helix is only about 2.5 nanometres (one ten-millionth of an inch) wide—too thin to be seen with any light microscope. (A complete turn of the helix is about 10.5 letters long.) But the whole DNA molecule is extremely long: the largest human chromosome, number 1, is composed of 220 million letters, and would be 85 mm (3.4 in) long if stretched out fully. If all the DNA in your cell were lined up, it would be about 2 m (6–7 feet) long! These enormously long, thin, sticky strands must be packed into a microscopic cell and then maintained without forming a mess of tangles and knots. The cell needs complex machines to do all this. These machines are amazing, complex, and a testimony to the genius of our Creator. When DNA is decoded (that is, when the information is used to create a protein), the two strands of the double helix must be separated. And during reproduction, each strand is copied independently. This requires special motors called DNA helicases. They are ring-shaped, with a hole for the DNA to pass through. But, since they are motors, they also need fuel. Helicases are powered by a ‘fuel’ called ATP, which is made by another motor, ATP-synthase. Using ATP as an energy source, a cyclic change in shape runs around the helicase ring at about 10,000 rpm—about the speed at which a jet engine turbine rotates. The helicase rapidly runs along the DNA and separates the two strands at the replication fork. Then, many other machines take care of decoding the DNA and putting the strands back together or copying the strands. This must run very fast, because the DNA copying speed is 1,000 letters per second and the helicase must stay ahead of the copying machines.