21
Protein Traffic within the Cell
Figure 86. Entries into and departures from the cell constitute a heavy traffic, which the cell membrane is responsible for supervising. The membrane admits essential and useful substances to the cell, while refusing entry to the others. Proteins are the main elements of that traffic.
Every cell in every human being contains more than a million protein molecules, of thousands of different kinds.16
In addition, these proteins are constantly renewed. Once every month, they are separated into the amino acids that comprise them and reproduced according to the cells’ needs.17 At the end of complex processes known as protein synthesis, they are combined together again within the cell.
Here, we wish to concentrate on the protein traffic flow that results from the newly produced proteins changing places inside the cell. Because the cell immediately begins using part of these proteins, they must be transported to the sites where they will be used.
Figures 87 and 88. After receiving instructions as to where to go in the cell—and how—newly synthesized proteins go where they are programmed. There exists a perfect order in this world, too small to be seen with the naked eye.
One portion is sent to the cell’s “protein warehouse,” to be used at a later date. Proteins to be used outside the cell membrane are removed from it under the supervision of the cell membrane itself. At this point, proteins entering the cell from the outside—again under the cell membrane’s supervision, represent a significant part of this heavy protein traffic. In short, there is considerable activity in the cell, despite its microscopically small size (Figure 86).
This activity is managed by an extraordinarily organized system. As you know, the postal code was originated with the aim of sending mails quickly to the correct destination, with the fewest errors and in the most efficient way possible, thus increasing the efficiency of communications between individuals and corporations. But recent research has revealed that a similar mechanism exists inside the cell.18
Proteins are synthesized by hundreds of “original” proteins combining according to various predetermined plans. One significant, chain-shaped section that consists of between 10 and 30 amino acids comprises the protein’s “postal code.” To put this another way, the postal code written on any envelope consists of (depending on the country) a combination of numbers and/or letters, while the “code” in any protein consists of various amino acids. This code is located in one end of the protein molecule, or else inside it. Thus every newly synthesized protein receives instructions regarding where it should go, and how to get there.
Let us now examine the protein’s journey inside the cell in greater detail (Figures 87 and 88).
When we look at how every new-synthesized protein is to pass to the endoplasmic reticulum region, for instance, we see the following: Firstly the code is “read” by a molecular component known as SRP—another protein with the best possible design for deciphering the code and helping the protein find a channel through which to pass. It solves the special information in the protein and then combines with it, acting just like a guide. Together, the SRP component and protein later attach to a special receptor that is waiting for them in the endoplasmic reticulum membrane, and the protein attaches to the entry channel. With the receptor being stimulated in this way, the channel in the membrane opens—at which point, the SRP separates from the receptor.
All these processes take place with flawless timing and in perfect harmony. But at this stage, the protein faces another problem. As we know, proteins emerge through being shaped by the bending and folding of amino-acid strings. As a result, it is impossible for proteins to pass through the endoplasmic reticulum membrane, which is only 0.0000002 millimeters in diameter. Now, however, a flawlessly designed plan comes into play, because this problem has been already solved well in advance. The ribosome that produces protein does so in the form of an unfolded chain, whose chain structure permits the protein to pass through the membrane. Once the passage process has been completed, the channel closes until another crossing takes place.
After the protein has entered the endoplasmic reticulum region, the task of the “code” section comes to an end. Therefore, specific enzymes separate that section from the protein, which then bends and assumes its three-dimensional form. The situation in question is analogous to how the postal code no longer has any meaningful function once the envelope has arrived at its destination. The enzymes in question know which of the hundreds—and sometimes, even thousands—of amino acids on the protein they must break off, and act with that awareness. That is another miracle altogether, because if any of the amino acids constituting the protein itself are broken off, instead of the amino acids that comprise the code, then the protein will lose its function. As we have seen, a great many parts work together in perfect harmony at every stage. It is self-evident that this harmony does not stem from any feeling of awareness and responsibility originating in these tiny molecules.
The fact of the matter is that the cooperation among the proteins, the SRP molecule, the ribosome, receptor, protein-entry channel, enzymes, organelle membrane and molecules involved in a great many other processes not described here, is utterly flawless. Even taken alone, the “postal code” system in the cell is a proof of God's magnificent creation. A system that mankind has been using for only the last 40 years functions inside trillions of cells in the depths of billions of human bodies.
No doubt that God, Lord of infinite mercy and compassion, has created all things, from atoms to molecules and from proteins to cells, and that He has placed these at our service. That being so, our duty is to reflect deeply on the countless blessings of our Lord and to give proper thanks to Him.
22
Chemical Communication in the Nerve Cell
Figure 89. Every neuron produces a different chemical messenger, unique to itself. To state that another way, every neuron works like a factory producing chemical messengers to be used in communication.
The links between neurons, or nerve cells, are established both by electrical signals and by means of chemical signals. Both forms of communication contain significant marvels.
In this section we shall be concentrating on various aspects of chemical communication, established by messenger molecules that comprise the spinal neurotransmitter. These are produced in the body of the nerve cell, carried along the axons (the long arms of neurons), and stored in miniature “bubbles” at the axons’ terminals. Each bubble contains some 5,000 messenger molecules.19 And recent research has shown that every neuron produces different chemical messengers.20 To put it another way, it resembles a chemical plant in which the various tools to be used in communication are produced. (Figure 89)
Figure 90. A chemical messenger molecule establishes a link with a different receptor. The message conveyed by the messenger molecule is thus perceived by the receptor neuron. The neuron that transmits the signal may be described as the transmitter and the receiving neuron as the receiver. These two come face to face at the synapse junctions. The distance between them is approximately 0.00003 millimeters (1.1811 inches).21 The electrical signal sets in motion the messengers at the end of the nerve-cell axons. Bubbles filled with chemical messengers attach to the cell membrane and release the molecules inside them into the spaces, or synapses between neurons. The message carried by the messenger is forwarded to receptors on the receiving neuron’s membrane. There is a particular receptor with which each messenger molecule connects. Thus the message carried by the messenger molecule is perceived by the receiver neuron (Figure 90).
Every stage of the communication process described here in the briefest of terms involves processes not yet completely understood. Indeed, scientists state that their knowledge regarding the nerves’ transmissions is still indistinct.22
Consider, for instance, just the fusion of the bubbles to the cell membrane. The event we describe as “fusion” in fact refers to a very special bonding, analogous to adding of a single component or update to a highly advanced computer.
At this point, the following considerations come to mind: the addition of any part to a computer is preceded by highly complex engineering calculations. Otherwise, inevitably, the new part will be incompatible or may even damage the computer. Of course, fusion compatible with the cell membrane, far more complex than any computer, does not taken place haphazardly. No doubt all these complex processes take place under the control of God, Who created and regulates them.
23
Nitric Oxide: A Skilled Messenger
Nitric oxide (NO) is a colorless, but toxic gas obtained by the oxidization of nitrogen—a molecule formed by the combination of one nitrogen and one oxygen atom. Despite its toxicity, this molecule has an attribute of the greatest importance for human life. Over the last 20 years, intense research has revealed that this molecule undertakes a fundamental task in communication among cells. Results of this scientific endeavor have shown that nitric oxide is a hormone produced naturally in the human body, as yet another chemical messenger that plays a strategic role in the regulation of functions in the nervous, circulatory, immune, respiratory and reproductive systems.
Figure 91. The endothelial cell produces molecules of nitric oxide (NO).
One location where NO undertakes a most important duty is in the veins. The internal diameter of the veins is not fixed, but expands and contracts according to our activities, thus playing an important role in regulating our blood pressure. Thanks to this immaculate system, the body’s needs are met, even while vary according to the surrounding environment. When you play sports, your blood vessels expand to supply the increasing demand for blood flow; and following injury they contract, reducing possible blood loss—all as a result of the ideal system in question.So how is it that the veins know when to expand and when to contract? Research has revealed the presence of a chemical messenger: the NO molecule. It is this molecule, consisting of two atoms, that issues the command for blood vessels to expand and contract.
Let us now examine the splendid facilities that produce NO in the depths of your circulatory system.
Under an electron microscope, veins can be seen to have a perfect structure, in inverse proportion to their size. For example, 10 capillary vessels aligned side by side are no thicker than a human hair. These narrow vessels’ internal walls are covered by a layer consisting of flat-muscle cells; expansion and contraction of the veins take place as a result of these muscles’ activities. The muscle cells do not come into direct contact with the blood, because the endothelial cells form a membranous layer between the muscle cells and the blood flow.
Figure 92. NO molecules transmit vitally important messages to a special enzyme called GC.
Like links in a chain, these cells combine together to comprise the endothelial layer. Until the 1980s it was believed that these cells had no other effect than to facilitate the flow of blood in the veins. The truth emerged only later, when it was realized that one of the endothelial cells’ responsibilities is to produce the messenger molecule NO (Figure 91).
If we compare the endothelial cell to a factory, you can think of the NO molecules as its products. The life span of each NO molecule is about 10 seconds, but NO is created to transmit the messages it carries during that brief span—which it does in the most perfect manner. The messenger NO molecules secreted by the endothelial cells begin being carried by the blood in all directions at high speed. Those that move towards the flat-muscle cells enter these cells’ membranes. The highly selective flat-muscle cell membrane recognizes the NO and permits it to pass through. The NO molecules entering the cell are immediately located by a special enzyme known as GC, and transmit their vitally important messages. A series of complex chemical reactions are thus initiated inside the cell (Figure 92).
These proteins, which we referred to as messengers, are molecules, a mere 0.0000001 millimeter in size. These molecules work like a mail carrier, finding the enzyme GC to which the messages they carry are “addressed.” The message is forwarded to the correct enzyme, every single time. In addition, these messenger molecules’ lifespan is very limited, yet they never make any errors of timing. The message-bearing NO molecules have no compasses or other devices to help them find their way, yet they never become lost.
During this process, the speed of the NO molecule is reminiscent of communications established by Internet technology, or e-mail. NO acts just like an electronic postal system, transmitting a great many messages to their correct destinations at a very high speed.
Figure 93. The enzyme GC converts GTP, energy-bearing molecules, into cGMP. The GC in the flat-muscle cells, receiving the messages carried by the NO, then goes into action. This worker enzyme’s duty is to convert GTP, an energy-carrying molecule, into cGMP. The many reactions taking place during this process have not yet been fully understood (Figure 93).
To explain it as simply as possible, as a result of the enzyme activities, the calcium concentration in the muscle cells decreases, leading to the fibers separating and the muscle cells expanding. In this way, the veins themselves expand. The message carried by the NO molecules play a vitally important role in the regulation of the pressure inside your veins.
It must not be forgotten that what is described here is just one of the billions of complex communication processes continuing at every moment inside our bodies.
At this point, a number of questions need answering: How is it that unthinking, unconscious NO molecules so perfectly recognize systems that even the world’s most esteemed academics have been unable to unravel? How do they know when to go into action or stop, right down to the millisecond? As soon as they are produced, how can they forward their messages at high speed, to exactly the right sites and at exactly the right time, as if they had received detailed instructions?
No doubt NO cannot perform all these wondrous tasks of its own accord. This molecule, like the millions of other molecules in nature, is the work of a flawless Creation. And for thoughtful people, it is just one of the proofs of God's infinite might and knowledge.
We will show them Our Signs on the horizon and within themselves until it is clear to them that it is the truth. Is it not enough for your Lord that He is a witness of everything? What! Are they in doubt about the meeting with their Lord? What! Does He not encompass all things? (Surah Fussilat, 53-54)
24
The Endothelial Cell: A Nitric Oxide Production Center
An amino acid by the name of L-arginine; the NO synthesis enzyme; nicotinamide adenine dinucleotide phosphate; calmodulin; oxygen; flavin mononucleotide; flavin adenine dinucleotide; tetrahydrobiopterine ...
Probably most people never have heard these words ever before. Yet the endothelial cell knows all these microscopic compounds very well and uses them for its production of the NO molecule (Figure 94).
Figure 94. The endothelial cell works just like a factory, accurately identifying microscopic substances and using them to produce NO molecules.
Factories manufacturing chemical products using modern-day technology are trillions of times larger than endothelial cells. Nonetheless, the advanced technology of the microscopic factory known as the endothelium is far superior to that of any human technology.
The endothelial cell knows which chemical substance it has to use, and in what proportion, in order to produce the nitric oxide molecule. There is never any incidence of wrong or incorrect production. For example, it does not produce laughing gas (N2O) instead of NO. Remember, were the endothelial cells to produce fewer messengers than necessary, our veins would contract and our blood pressure would rise rapidly, leading to a heart attack. In the event of excessive production, our veins would over-expand, our blood pressure would plummet, and this would result in shock. However, the endothelial cells never make such possibly fatal errors.
The cells in question are always ready to produce. When the need arises, they immediately go into operation and start production. These miniature factories work very efficiently. They never store the messenger NO molecules they produce, so the problems associated with storage thus never arise.
There are no undesirable, harmful side products from these extraordinary factories in the depths of our veins. When you consider that a great many health-threatening problems—such as global warming, acid rain and environmental pollution—all stem from chemical wastes, the endothelial cells’ achievement can be better understood. That is because the NO molecules are broken down in as brief a space of time as 10 seconds, never accumulating in the body long enough to give rise to any harmful side effects. All this means that the endothelial cells use ideal methods in their manufacture of chemical products.
In the same way that a factory’s systems indicate the advanced technology their designers must have mastered, the endothelial factory shows the infinite intelligence and knowledge of our Lord, with His sublime creative artistry. Like the other 100 trillion cells in our bodies, this microscopic factory acts under the inspiration of God.
He is the First and the Last, the Outward and the Inward.He has knowledge of all things. (Surat Al-Hadid, 3)
25
The Power Station in the Human Body
Figure 95. Many different enzymes work in just about every stage of the cell’s production of energy. In a most conscious manner, enzymes that complete their tasks at a later stage take over from other enzymes in an earlier stage. This change of enzymes happens with no confusion.
Figure 96. The power station in our cells, just 1/100 millimeter in size, is far more complex than any oil refinery or hydroelectric station.
The energy we need to stand up and walk, stand on our feet, breathe, and open our eyes—in short, for our very survival—is produced in power stations in our cells known as mitochondria. The aptness of this comparison can clearly be seen when we examine the processes that take place in these microscopic organelles.
Oxygen plays the major role in the production of energy in the cell, but oxygen also has many assistants. In just about every phase of energy production, several enzymes enter the equation with their exceedingly conscious behavior; the enzymes that complete their functions in one stage make way for others in the next. Thus thanks to dozens of intermediate processes and the countless chemical reactions and hundreds of different enzymes involved in these processes, the energy stored in foodstuffs, having been digested, is transmuted into a form that can benefit the cell. During these many changes, these enzymes never create any confusion, and their order never goes wrong. All the components work together as a disciplined team (Figure 95).
We can say that the power station inside our cells, just 1/100 millimeter in size, is more complex than any petrol refinery or hydroelectric station (Figure 96).
Figure 97. Enzymes work just like expert chemical engineers in their chosen fields to produce the energy needed by the human body.
A gasoline refinery is built and run by engineers who know what petroleum is, who have analyzed crude oil under laboratory conditions and who act in the light of that knowledge. It is impossible even to imagine that people with no knowledge and experience could build a functioning oil refinery (Figure 97).
The production of energy in the living cell, which is far more complex than oil production, also requires information. Yet it would be ridiculous to suggest that a cell has the ability to learn anything at all. How, therefore, does this energy production take place?
Naturally, no cell has the opportunity to learn any biological function in the literal sense of the word. If the cell were unable to perform any function at the moment it first came into being—as evolutionists maintain—then it would be impossible for it to obtain the ability to do so later. That is because oxygen, which plays the paramount role in energy production, has harmful effects on the cell. The cell has to emerge together with the ability to utilize oxygen. This is just one of the proofs that cells cannot have emerged by chance, but were created in a single moment by Almighty God.
This artistry that God located in a space as small as 1/100 millimeter, shows us the infinite nature of His might.
26
The “Bacteria-Destroying Machines” in the Liver
Through the food we eat, the air we breathe and in many other ways, large numbers of bacteria constantly enter our bodies. Those with possible harmful effects need to be neutralized if the body’s working systems are not to be damaged. For that reason, our bodies contain cells equipped with perfect memories whose sole purpose is defense. However, various additional measures have been taken for defense, which is yet another example of our bodies’ flawless creation. One of these measures is the defense cells in the liver, which can be described as a strategic point inside the circulatory system (Figure 98).
Figure 100. Kupffer cells occur specially in the liver, the ideal place for them. These cells, known as Kupffer cells, neutralize any harmful bacteria reaching the liver from the intestine by way of the bloodstream by digesting them—in less than 0.01 of a second! How are these unconscious cells able to distinguish, among the great number of bacteria entering the body, beneficial ones from harmful ones? Unaware of what properties bacteria possess and what functions they will fulfill in the body, why do they destroy some bacteria while leaving others untouched? The answer to these questions is without doubt the matchless creative artistry of Almighty God (Figure 99).
Another question we need to ask is why the Kupffer cells have been located in the liver. Why the liver, and not some other organ in the body? Here once again, we encounter evidence of our bodies’ flawless creation. If these cells were in some other organ but not in the liver, then they would be less effective in purifying the blood of bacteria. That is because after blood is cleaned in the liver, it enters the bloodstream to travel through the entire body. After being purified in the liver, fewer than 1 bacterium in 100 manages to enter the general circulation.
Located in the liver, Kupffer cells quickly neutralize any bacteria reaching the liver from the intestines. This whole system is the work of God’s immaculate creation.
Could blind chance have located the all-important Kupffer cells in the liver when there are so many other organs available? (Figure 100). Of course, these cells themselves do not identify the best place for them to settle. No one cell among the 100 trillion cells in the body has the consciousness with which to settle in such a location. The most perfect planning is essential for such a settlement to take place. Almighty God creates every detail in this system at every moment.
27
DNA Replication
Figure 101. As the DNA’s two arms separate from one another, helix-stabilization enzymes (HSE) hold both arms fixed to prevent them rewinding around each other. In the middle: The arms of a DNA molecule separating from one another.
Figure 102. After the DNA has been divided into two parts, polymerase enzymes complete the missing halves of both arms, using the materials readily available around them.
As you know, cells replicate themselves by dividing. But what happens to DNA as a result of this division process? There is one single DNA strand in each cell. Yet the newly emerging “twin” cell will also need complete DNA of its own. In order to achieve this, a series of processes takes place, every stage of which is an independent miracle. As a result, an exact copy of the “original” DNA is formed shortly before cell division takes place, and this copy is transferred to the new-formed cell.
In order to replicate itself, DNA first separates itself into two opposite parts. This takes place in a most interesting manner. The DNA molecule, which resembles a spiral staircase, split down the middle, much like a zipper being unzipped, by an enzyme called DNA helicase. As the arms of the DNA separate from one another, helix-stabilizing enzymes keep both arms fixed, in order that they should not wrap round one another again (Figure 101).
The DNA has now been divided into two halves. The missing halves of each are completed with materials available around them. The task of making good these gaps is performed by DNA polymerase. Thus, two new DNA molecules are produced (Figure 102).
Figure 103. DNA replication processes are carried out at great speed. Every minute, 3,000-step nucleotides are produced and all these steps are controlled by the enzymes responsible.
The new DNA molecules that emerge during this matching are checked many times by supervisory enzymes. If any error has taken place (and any such error could have fatal consequences), it is immediately identified and corrected. Incorrect DNA codes are torn apart, replaced with correct ones, and then re-assembled. All these processes take place at such a dizzying speed that a 3,000-step nucleotide is produced in a minute, during which time all these steps are checked and the necessary adjustments made many times (Figure 103).
As a result of external factors such as radiation or pollution, more errors than normal may occur in the newly produced DNA molecule. This time, the ribosomes in the cell begin to produce DNA-repairing enzymes in light of the commands coming from the DNA. Thus the DNA is protected, and the survival of the daughter cells—and the entire organism—is ensured (Figure 104).
Figure 104. Just like robots, ribosomes in the cell begin producing DNA-repair enzymes according to instructions from the DNA.
Unknown to you, countless processes and supervision are performed, and precautionary measures are taken, over the course of the day, to allow you to continue with your life in a problem-free manner, with an astonishing care and sense of responsibility. Each task is performed flawlessly and successfully. Almighty God has placed countless atoms and molecules, from the smallest (hydrogen atoms) to the largest (polymer molecules), at our service, in order for us to live agreeable, healthy lives.
One of the most amazing aspects of these enzymes, which ensure the production of DNA and also monitor its structure, are proteins produced in the light of information recorded in the DNA itself, and under the command and control of that same DNA. This system is so magnificent and interconnected that it’s impossible for it to have come into existence by chance. DNA must exist in order for the cell to be, but the cell must exist in order for DNA to be—and the cell has to exist in order for both to be.! Moreover, the cell has to be fully formed, from its membrane down to all its tiny, complex organelles.
The theory of evolution, which claims that living things developed in stages as a result of consecutive beneficial coincidences, has no answer to the question of whether DNA or the necessary enzymes described above came into existence first. For a cell to survive, let alone reproduce, both the DNA and enzymes need to exist at one and the same time. And that is impossible in terms of the imaginary mechanisms proposed by the theory of evolution.
28
Repair Enzymes
DNA has the ability to repair itself and make good its own deficiencies— this is just one manifestation of God’s creative artistry and omniscience.
Errors that might arise in DNA as a result of external factors are identified and repaired by DNA control mechanisms. These consist of enzymes produced in the light of the information in the DNA itself. Although there are different repair mechanisms, the basic principle is that the damaged nucleotide carries out repairs in the light of information it receives from an undamaged nucleotide. This process generally takes place in three stages:
1. After being identified by the enzyme known as DNA nuclease, the damaged part of the DNA string is broken off, thus forming a gap in the DNA spiral.
3. The DNA repair is not yet finished! A break has formed on the sugar-phosphate line on the repaired area, which is repaired by the enzyme DNA ligase.
This whole situation is quite astonishing. Almighty God, Who is free of all imperfection, exhibits the glory of His creation by creating tiny molecules with such extraordinary abilities. Any rational person of good conscience, as his knowledge of living things and the entire universe increases, will grow in submission to the infinite might of God and will call on God’s name in the finest terms.
29
Protein production
Figure 105. When a new protein needs to be produced, messengers which are themselves proteins, carry the request for protein production to the cells of the organ concerned.
Protein production in the cell is one of the miraculous phenomena created by God. Every cell operates like a factory, using the most advanced technology and organization. In this micro-world, which is visible only under the most powerful microscopes, extraordinary events take place.
Let us examine the main outlines of this protein factory that works with the most flawless and perfect efficiency:
1. Whenever the body feels the need for any protein, a message expressing that need reaches the DNA molecule in the nuclei of the cells where that production is to take place. Here, a very important point is to be noted: Whenever there arises a need for any protein in the body, certain messengers—themselves proteins!—can find all the relevant locations in the body, know where they must go, and then transmit their message to the right place in the proper form. The protein that establishes this communications finds its way in the total darkness of the bloodstream, without losing its way, losing the message it carries or doing any harm to any part of it (Figure 105).
2. To request the formula for a protein from DNA, a special language is used. This language has an alphabet which scientists designate as consisting of four letters, A, G, C and T. The production of the appropriate protein is of the greatest importance in order that there will be no impairment of the processes inside the cell, and for the need to be met in an accurate manner—in short, to maintain the cell’s very survival. Therefore, after the message arrives concerning the need for a particular protein to be produced, the correct information needs to be selected and extracted from the DNA.
As the arms of the DNA separate from one another, an enzyme prevents them winding around one another again. This enzyme is marked with green in the illustration.
But who makes that selection? An enzyme known as RNA polymerase, whose work is exceptionally difficult. First and foremost, it must select the letters regarding the protein to be produced from among the DNA molecule, which consists of 3 billion letters. The way that RNA polymerase finds and extracts information of just a few lines from those 3 billion units of DNA information is comparable to finding a few specific lines in a foreign language, with no description or index of it being available, from an encyclopedia consisting of 1,000 volumes.
3. In order for the copying process to begin, a very important obstacle has to be overcome. The entwined arms of the DNA molecule need to be separated, and this is again the task of RNA polymerase. Attaching itself to the first 3 letters of the gene to be coded, the RNA polymerase opens up the DNA rungs—which resemble a spiral staircase—as if it were unfastening a zipper. It does this at a very great speed. In fact, because of that very speed, there is a danger of the DNA heating up and getting damaged. Yet the system has been laid out so perfectly that this danger has been foreseen.
Thanks to a series of precautions taken beforehand, the danger of overheating is eliminated; as if it were aware of the possible danger, a special enzyme attaches to the ends of the opened DNA string and blocks this friction. As we’ve seen, special enzymes then prevent them winding around each other during the DNA opening process. Were it not for these enzymes, then it would be impossible for the order docket known as messenger RNA to be copied, because the arms of the DNA helix, parted like the teeth of a zipper, would again wind around each other before the copying process even began, and the resulting friction would damage the structure of the DNA. As we have seen, dozens of enzymes and proteins are involved in every stage of the process, yet all fulfill their responsibilities to the letter, in perfect harmony.
4. After these special precautions, there are still a few more hurdles to be overcome. For instance, the information containing the amino-acid sequence in the desired protein may lie anywhere in the long DNA molecule. In that case, how is the polymerase enzyme to copy codes indicating information—in other words, the amino-acid sequence— in different locations?
The regions marked 1 through 7 contain information that does not need to be “read.” Enzymes set out these regions bend them to the outside, as shown in the illustration.
It cannot break the DNA, nor skip over unwanted codes. If it continues directly along the same lines, it will copy unnecessary data, and the desired protein will fail to appear.
Figure 106. When the enzyme RNA polymerase reaches the stopping codon, it understands that the copying must stop, and halts the process.
The solution to this problem takes place with an extraordinary phenomenon. The DNA, as if it were aware that it must assist in the copying process, bends in such a way that the region containing the unwanted string of code appears on the outside. Thus the ends of code sequences that must be read consecutively, but which are separated from one another because there are other codes between them, actually join together. In this way, the codes that need to be copied appear in a single line, and the polymerase can easily copy the protein in the order docket.
5. The extraordinary events that occur in the copying of the order docket from the DNA, exhibiting the flawless nature of the creation of Almighty God, do not end here. The copying units also must be halted, or else the polymerase will copy the entire gene from beginning to end. At the end of the gene coding the protein is a codon indicating that the gene has come to an end. (The word codon refers to any triple group of nucleotides that constitute the DNA code.) When the RNA polymerase arrives at the codon, it understands that the copying process is to end. And at this point, the messenger RNA bearing the message for the protein separates from the DNA (Figure 106).
Great care is again taken at this point, because the messenger RNA will cover a considerable distance, exiting the nucleus and going to the ribosome where production is to take place. It is also essential that the message it carries should come to no harm. Therefore, it emerges from the cell nucleus under the protection of various special enzymes.
Protein production is by no means limited to these phases. However, the miraculous events that have occurred up to now are some of the proofs of God’s sublime artistry and infinite knowledge.
30.
The Final Stage of Protein Production
Figure 107. After the information needed for protein production has been copied from the DNA, it is brought to the ribosome by messenger RNA and released. The messenger RNA finds the ribosome without losing its way.
After the information in the DNA needed for protein production in the cell is located and copied, it must reach the factory—in other words, the ribosomes—where production is to be carried out. These organelles, present in every cell, lie quite a distance from the DNA in the nucleus and are distributed throughout the cell’s cytoplasm, the cell’s internal fluid.
Production orders must be forwarded to these factories in perfect form and at high speed. The messenger RNA (mRNA) finds the ribosome from among all the many organelles inside the cell without losing its way. When the mRNA locates the ribosome, it settles onto its exterior in the form of a line.
The information belonging to the amino acid sequence of the desired protein has thus reaches the production center. Now, messages begin being sent to the other regions of the cell for the raw materials—amino acids, in other words—necessary for the protein to be produced and brought in (Figure 107). 23
The task of searching for and finding the amino acids to be used and of bearing them to the ribosome belongs to transporter RNA (tRNA). There are 20 varieties of amino acid in every living cell. Each one of these amino acids, or raw materials, is carried by a transporter unique to itself. 24 The way amino acids bond to the tRNA that will transport them takes place as the result of a series of complex processes.
Every tRNA serving as transport carries every amino acid to the place in the ribosome set out in the production instruction, ensuring that there is no impairment of the production function.
The flawless discipline seen in these unconscious molecules, the way they behave as if possessed of awareness and responsibility, is proof that each has submitted to God, the Lord of sublime might and reason, and behaves under His control.
The information and requisite raw materials for the protein to be produced are now ready. Yet first, there is another problem to be overcome. As we have already seen, the production data—the order, in other words—is written in a special language in the DNA. Production must take place according to the data written in that language. However, the strings of amino acids to be used as raw materials are “written” in another language.
The problem may be better described thus; the written instruction in the order form is in the language of the code comprising the DNA—that special “language” consisting of four letters. The proteins to be produced are communicated in a different language, with a 20-letter alphabet (because there are 20 varieties of amino acid comprising proteins). Thus, the production information coming from the DNA is not in any language the amino acids can decipher. As a result, in order for the amino acids to understand which information from the DNA is referring to, they must translate the DNA language.
In order for life to continue, the ribosome factory has been equipped with a mechanism that resolves this problem in a most perfect manner. A system has been created that translates between the two different languages used during production in the ribosome. This translation system, known as the codon-anticodon method, works in a manner far superior to even the most advanced computer centers. Just like an interpreter expert in two different languages, it turns the protein information written in the DNA language (consisting of four letters) into the protein language (consisting of 20), stating which amino acids are to be laid out alongside one another. As a result, the desired protein is accurately produced.
Worthy of particular note is the absence of any error in this translation process. There is only room for one or two errors in the production of the thousands of proteins necessary for the survival of the cell, and thus of the living things. No man-made technological apparatus nor the most careful and expert human beings could translate and write a text such as a protein—the equivalent to 200 novels—in such a flawless, perfect manner.25 However, these molecules, which behave under the control of God at all times, do everything to the letter. To rational believers, all these are manifestations of God’s miracles.
16- Gunter Blobel, “Intracellular Protein Traffic,” 2000, http://www.hhmi.org/research/investigators/blobel.html
17- Blobel, op. cit., , http://www.hhmi.org/research/investigators/blobel.html
18- The Nobel Foundation, Press Release: “The 1999 Nobel Prize in Physiology or Medicine,” 1999, http:// www.nobel.se/medicine/laureates/1999/press.html
19- E. Kandel, J.H. Schwartz, T.M. Jessell, Principles of Neural Science, New York: McGraw-Hill, 2000, p. 277.
20- Eric H. Chudler, “Making Connections—The Synapse,” 2001, http://faculty.washington.edu/chudler/synapse.html
21- E. Kandel, J.H. Schwartz, T.M. Jessell, Principles of Neural Science, p.176.
22- Axel Brunger, “Neurotransmission Machinery Visualized for the First Time,” 1998, http://www.hhmi.org/ news/brunger.html
23- "Cells’ Energy Use High for Protein Synthesis" in Chemical & Engineering News, August 20, 1979, p. 6.
24- Albert Lehninger L., Late University Professor of Medical Sciences, Johns Hopkins University; David L. Nelson, Professor of Biocemistry University of Wisconsin, Madison; Michael M. Cox, Professor of Bochemistry, University of Wisconsin, Madison: Principles of Biochemistry, Second Edition, New York: Worth Publishers,[Date?] , p. 905.
25- Mahlon B.Hoagland, Hayatin Kokleri (“Origins of Life”), Tubitak Populer Bilim Kitaplari 12th ed., May 1998, p. 31.
Hiç yorum yok:
Yorum Gönder