Imagine the coiled cord that leads from a telephone receiver. A long cable has been squeezed into a much shorter distance, but in such a way that it can be extended if necessary. Nobody seeing that cable could possibly imagine that it had assumed that shape by chance, because the place where the cable is used, its purpose and the ease it affords are all signs of an intellect and conscious knowledge.
The DNA in human cells has a similarly spiral shape, but is far more regular, longer and more convoluted. There is enormous wisdom behind the use of this shape. DNA's extraordinary data capacity, which we shall be discussing shortly, and the way it is compressed into a minute space, are made possible thanks to this special form. DNA, which measures 4 meters (13.12 feet) when its spiral is fully extended, takes up no more space than one two millionth of a millimeter, and is hard to see even under an electron microscope.29
DNA is Reminiscent of a Highly Regular Spiral Staircase
The DNA molecule is a coiled helix, consisting of two spirals, rather like a staircase. The coils in the DNS spiral have an exceedingly regular structure. The vertebrae consisting of sugar and phosphate in both DNA chains revolve at an equal distance around a common axis and twist in the same direction, from right to left. Moreover, there is no haphazard sequencing in the steps between the two arms. The bases that make up the rungs form an angle of 90 degrees to the spiral axis, giving the DNA strip its highly regular, staircase-like appearance.
The steps are joined to one another with a special locking system. The four different components of the rungs –adenine, guanine, cytosine and thymine– are of different sizes. The adenine and guanine bases are large, and cytosine and thymine are small molecules. The dimensions of the molecules that will be opposite one another have been determined in such a way as to ensure equal spaces at every point on the spiral staircase. In order for the steps to be always regular, guanine always pairs with cytosine, and adenine with thymine. Thus small bases always being opposite large ones in the DNA molecule means the distance is stable at every point. The result is a regular staircase extending with no interruptions. However, if the base adenine were to be paired with guanine just once, instead of with thymine, it would be impossible for the helix structure to proceed in a regular manner. Any error in the sequence might thus entirely impair the molecule's chemical structure and prevent the data being used, copied and transmitted. This again indicates that the sequence cannot be the work of chance.
The distance between the turns of neighboring base pairs is also stable. This system ensures equidistance between the staircase coils, some 10 base pairs –in other words, 10 steps– form a complete revolution of 360 degrees.30 DNA coils a billion times a second, and the staircase steps twist by performing their spiral movement.31 This action plays a very important role in DNA's performing two vital functions--directing the formation of protein and self-replication. Prof. Werner Gitt, director of the German Federal Institute of Physics and Technology, says this about this special structure:
The coding system used for living beings is optimal from an engineering standpoint. This fact strengthens the argument that it was a case of purposeful design [Creation] rather than fortuitous chance .32
Importance of the Bonds used in the Building the Spiral
The dual backbones of the long DNA molecule –or the banisters of the staircase– are very strong, made up of consecutive sugar and phosphate molecules. These molecules attach to one another with a special bond known as ester covalent bonds. These are exceptionally strong and it is very difficult to break them. This strength provides protection against harmful factors that might impair genetic information.33 The existence of these bonds makes the DNA molecule resistant and stable even while the DNA molecule is in a single-strand form.
However, there is a risk of damage to the DNA spiral structure as the coils unfold. For that reason, the spiral needs to be strong and stable enough to protect its structure but also elastic enough to be opened up very quickly so that the information can be easily used. In fact, a combination of powerful covalent bonds that protect DNA's basic molecular structure of, and weaker hydrogen bonds that can be broken more quickly, enables the elasticity-solidity problem to be overcome. Since the hydrogen bonds forming between the four opposed nucleotides are not as strong as ester bonds, they can easily be separated with less energy by means of such factors as pH variation (acid-base equilibrium), heat, and pressure. Weak bonds play a very important role in the shaping of the large molecules in an organism, and endow with elasticity the substance they compose. However, no breakage in the bonds ever takes place. Thanks to this distinguishing feature of hydrogen bonds, the information in the DNA molecule can be used whenever required.
The significance of the elasticity in the bonds is that the vital function of protein production is made possible by DNA being copied when cells divide, and that transmission is made possible by the elastic property of the bonds between them. Since the two chains of the DNA molecule are attached to one another only by hydrogen bonds, they can easily be unraveled and separated from one another. They can also, when necessary, recombine and form a new helix structure. No breakage or impairment ever takes place in the nucleotides that constitute the steps of the DNA chain during detachment or separation. While the hydrogen bonds in the center can easily separate from one another, no breakage or stretching ever develops in the long chains at either side, attached by means of covalent bonds. The molecular biologist Michael Denton describes the perfection in the biochemical structure of DNA:
The geometric perfection of the molecule is particularly evident in the fact that the strength of each of the five hydrogen bonds –the two between adenine and thymine and the three between guanine and cytosine– is optimal because each of the hydrogen atoms points directly at its acceptor atom, and the bond lengths are all at the energy maximum for hydrogen bonds. This is most remarkable, for it confers great stability on the molecule and makes for highly accurate base pairing during replication.34
On the one hand, there is a need for a sound and stable structure for the containing of genetic information, while on the other a flexible structure is required for the genes to be read and copied. So the strength of the bond between the two arms that make up the DNA helix has to be just right for it to fulfill its essential functions. And indeed, the DNA helix does have just the right level of strength and elasticity. If the bond between the DNA strips were any stronger, the two arms would stop moving and become fixed. But if the bond were weaker, the molecule would break apart.35 Yet by the will of Allah, the bonds that constitute DNA have the ideal structure to make the helix both highly regular and exceedingly functional.
The Importance of Phosphate in DNA
Phosphates keep together the nucleotide bases on DNA, because the DNA helix functions in an environment containing water, and water breaks down the bonds between phosphates and sugars. Thus it is both advantageous and essential that the phosphate groups in DNA be negatively charged. That negative charge eliminates the danger of the DNA being broken down in the watery environment surrounding it.
What compounds, other than phosphates, could establish a chemical bond and still manage to remain negatively charged? There are various possibilities. Yet none of these can form genetic information in the way that phosphate does. Silicic acid and arsenic esters break down rapidly in water. Although citric acid dissolves more slowly in water, it lacks the stability to maintain the molecule's geometry.36
Therefore, if phosphate did not have its own unique properties, the DNA's double helix could not form. No self-replication biochemical system could be established, and life would be impossible. The well-known professor of chemistry Frank Henry Westheimer says this: "All of these conditions are met by phosphoric acid and no other alternative is obvious."37 This situation and all the other details we have examined so far clearly show that our Lord has created the DNA molecule with miraculous properties. In one verse of the Qur'an, it is revealed that:
He knows what is in front of them and behind them. But their knowledge does not encompass Him. (Surah Ta Ha, 110)
14. Walter L. Starkey, The Cambrian Explosion, WLS Publishing, Ohio, 1999, p. 155.
15. Michael J. Denton, Nature's Destiny, Free Press, New York, 1998, p. 149.
16. Walter L. Starkey, The Cambrian Explosion, p. 41.
17. Lee M. Spetner, Not By Chance, Shattering The Modern Theory of Evolution, The Judaica Press Inc., 1997, p. 213.
18. The Incredible Machine, National Geographic Society, Washington DC., 1986, s. 43.
19. Walter L. Starkey, The Cambrian Explosion, p. 41.
20. Walter L. Starkey, The Cambrian Explosion, p. 41.
21. Richard Milton, Shattering the Myths of Darwinism, Park Street Press, Rochester, USA, 1997, p. 170.
22. David S. Goodsell, Our Molecular Nature, Springer-Verlag, New York, 1996, p. 39.
23. David S. Goodsell, Our Molecular Nature, Springer-Verlag, New York, 1996, p. 15.
24. Gerald L. Schroeder, TThe Hidden Face of God, 3, s. 188.
25. The Incredible Machine, National Geographic Society, Washington DC., 1986, p. 190.
26. James D. Watson, The Double Helix , Touchstone, 2001, p.52-54.
27. Michael J. Denton, Nature's Destiny, Free Press, New York, 1998, p. 152.
28. Daniel C. Dennett, Darwin's Dangerous Idea, Touchstone, New York, 1996, pp. 112-113.
29. Werner Gitt, In the Beginning was Information, p. 90.
30. http://genetikbilimi.com/genbilim/dnanedir.html
31. The Incredible Machine, National Geographic Society, Washington DC., 1986, p. 43.
32. Werner Gitt, In the Beginning was Information, p. 96.
33.http: // library.thinkquest.org /20465/DNAstruct.html
34. Michael J. Denton, Nature's Destiny, pp. 151,152 (emphasis added)
35. Ibid., p. 153.
36. Ibid., p. 406.
37. Ibid.
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