Belief at the Level of Molecular Biology
I am very sorry my Lord, God the Greatest, Allah the Magnificent, that I was so late to recognize your blessings in providing me with all these great miraculous molecules such as hemoglobin to perfect my life and health. Life was impossible without these molecules, and I just remembered their value when I get ill because of a disease that affects their function or production. I am very sorry because I didn’t thank you for your blessings, rather I questioned your presence, but now after I know the facts I will never forget you again, please forgive me.
I started to realize the miracle of human protein molecules when I was studying probabilities in calculus. I was amazed to realize that when we create a long password, the possibility of breaking it becomes more difficult the longer it is. A 50 letter password is impossible to break even if we use a super computer capable of 50 trillion calculations per second for thousands of billions of years. This is because we have 26 letters to create the password and when we calculate the probabilities it will be 26^50 which is an incredibly very large number. This immediately drew my attention to our subject molecular biology. Our human body vital functions depend largely on different types of specialized proteins such as hormones, enzymes, hemoglobin, albumin, collagen, etc… These molecules are synthesized from their building blocks the amino acids under control of genes and information encoded in our DNA. The number of the building blocks, the amino acids is 20. The size of the proteins may vary from small polypeptides less than 50 amino acids long to very large size of 27000 amino acids. Albumin a very vital protein is 585 amino acids long. Hemoglobin, the red pigment of our blood is a complex molecule and I will discuss it here as the basis of belief at the level of molecular biology.
To explain the existence of life in this planet two theories were proposed; evolution, and intelligent design creation. The idea of evolution depends largely on random slow genetic changes (mutations) that affect living species during very long periods of time, the bad changes will disappear and the good changes will persist according to the law of natural selection. The weakness of this theory comes from the assumption that very slow changes occur over very long periods of time to achieve gradual evolution. In the password example above we noticed that a very fast super computer of 50 trillion calculations per second was unable to break a 50 letter password even after thousands of billions of years. The age of the universe is estimated to be only 15 billion years, the sun 4.5 billion years, and our planet the earth is also 4.5 billion years. If we look at a small protein molecule of only 100 amino acids as a password, and the 20 amino acids as the alphabets, and we calculate the probability of achieving the correct sequence of this particular protein by chance it will be 20^100, an incredibly large number which will not be achieved by chance even if we use a super computer for millions of billions of years. It is this simple idea that renders the theory of evolution just impossible. The vital functions of specific proteins such as hormones and collagen depend largely on the accurate sequence of the amino acid chains which is called the primary structure of the protein. Any change of any amino acid in that chain may render that protein mal or none functioning leading to a particular disorder or disease. If we consider that there are millions of vital protein molecules working in the human body in great coordination and harmony, and if we disrupt this system in any way, a disease which may be fatal may occur; we may conclude that evolution has no rule in the presence of such a complex system; a suitable example of it is the hemoglobin molecule in our blood.
Hemoglobin is the molecule that gives our blood its red color. This molecule is essential for life as it is responsible for carrying oxygen from our lungs to the various tissues and organs. Hemoglobin contains four polypeptides; two alpha chains (141 amino acids), and two beta chains (146 amino acids). Each chain contains a heme-iron group.
Hemoglobin synthesis requires the coordinated production of heme and globin. Heme is the group that mediates reversible binding of oxygen by hemoglobin. Globin is the protein that surrounds and protects the heme molecule. The pairing of one alpha chain and one beta chain produces a hemoglobin dimer (two chains). The hemoglobin dimer does not efficiently deliver oxygen, however. Two dimers combine to form a hemoglobin tetramer, which is the functional form of hemoglobin. Complex biophysical characteristics of the hemoglobin tetramer permit the exquisite control of oxygen uptake in the lungs and release in the tissues that is necessary to sustain life. The genes that encode the alpha globin chains are on chromosome 16 and those that encode the beta globin chains are on chromosome 11. The expression of the alpha and beta genes is closely balanced by an unknown mechanism. Balanced gene expression is required for normal red cell function. Disruption of the balance produces a disorder called thalassemia. The two alpha and two beta chains hemoglobin is called adult hemoglobin (hemoglobin A), because it is not found in fetal life. The fetus requires higher oxygen affinity hemoglobin a two alpha and two gamma chains which is also encoded on chromosome 11 (hemoglobin F). The mechanism that suppresses the production of hemoglobin F and triggers the production of hemoglobin A at birth is unknown. However, if hemoglobin F persisted after birth in high percentage it causes a very serious disease called thalassemia major. Mutations in the globin chain are associated with the hemoglobin abnormalities, such as sickle-cell disease and thalassemia.
Sickle cell anemia a serious disease results from a change of a single amino acid in the beta chain. In position 6 the HbS had a valine, while the HbA had a glutamic acid. This tiny difference of a single amino acid somehow altered the properties of HbS in such a way that it made people very sick.
What did the valine substitution do to HbS? HbS can bind oxygen and transport it fine. But the valine causes molecules of hemoglobin to clump together. This, in turn, makes the cells take on the deformed sickle shape. The distortion of the cell's shape makes it mechanically fragile, and such cells disintegrate sooner. In fact, these cells last less than half as long as normal red blood cells. Obviously, loss of many red blood cells would lead to anemia. Another problem is that the deformed shape of the cells makes it difficult for them to pass through tiny blood vessels. They sometimes get stuck and block blood flow to vital organs and tissues.
Sickle cell disease was the first disease that was understood at the molecular level. It was caused by the change of a single amino acid, which in turn, was caused by a change in the DNA code for the protein. Nowadays fetal cells can be tested for presence of the sickle cell gene, by using DNA tests.
To summarize we have two optimal fully developed normal hemoglobin molecules; A and F. The A is the ideal for adults, and the F is the ideal for the fetus, but they can’t be substituted. Is this a master design creation or a randomly evolved phenomenon? We are not expecting to have any new mutations in the near future to improve these molecules and to produce a new for example super hemoglobin. Likewise, we have abnormal hemoglobin molecules such as hemoglobin S and we are not expecting any new mutations to produce other abnormal hemoglobins in the near future because if mutations occur they just occur very slowly over very long periods of time. As we explained before if we have super fast changes in nearly unlimited time we hardly may find the correct sequence for the proper globin chain even after millions of billions of years. The age of the universe is very short at only15 billion years; so the question is when did the needed experiments to produce the optimal alpha, beta, and gamma chains to produce the appropriate hemoglobin molecule, A or F took place? And then we can extend the questions to the other very important proteins such as albumin, Insulin, myoglobin, collagen, etc… all working in a marvelous harmony and coordination. In my humble opinion it is just next to impossible to explain the presence of this system on the basis of random slow evolution. It only can be explained on the bases of a wise, knowledgeable, capable designer who created all these beautiful systems.
Appendix:
To calculate for the probabilities of the 141 amino acid chain we do the following:
20^141, then we divide this by the speed of the super computer 50,000,000,000,000, then we divide by 60 seconds, then we divide by 60 minuets, then we divide by 24 hours, then we divide by 365 days, and we get the result in years needed to obtain the correct sequence by chance which is: 1.8*10^162 years, or approximately 200000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 years. Compare this with the short age of the universe of only 15000000000 years.