The biological structure of living beings is based on chemical compounds formed by carbon elements bounding to other elements or to themselves. These compounds are named as biological molecules, macromolecules or biopolymers. The elements in these compounds and the three dimensional structure in space that is formed is important information in a living system. Based on this information these molecules have the ability to recognize, like or dislike each other. In this perspective we can say that atoms and molecules act as if they have personalities and these personalities play an important role in forming various compounds with other atoms and molecules based on the conditions.
The widely accepted argument today is that the elements used as building blocks of life were first backed in the nuclear furnaces of stars under extra ordinary heat and pressure, undergoing a series of transformations and took their forms as we realize them on our earth. Among all the elements on our planet earth, the unique properties given to carbon and hydrogen elements has made the existence of carbon-based life forms possible.
Carbon combined with different elements in many different quantities and geometric arrangements, results in a vast assortment of materials with vastly different properties.
The molecules that are found in live organisms are created from different quantities, geometric arrangements and assortments of carbon, hydrogen, oxygen, phosphorus, nitrogen and sulfur. The base properties of carbon are playing an important role in creating these compounds.
Each carbon atom makes four bonds. Carbon may make bonds with other carbon atoms forming chains, branching chains or rings of linked carbon atoms. These properties given to carbon are important factors in the miracle called life.
When a carbon atom makes bounds with four hydrogen atoms methane gas is obtained (CH4). If we exchange the hydrogen atoms with oxygen atoms in methane we obtain carbon dioxide (CO2). If we exchange the hydrogen atoms with sulfur atoms in methane we obtain carbon disulfur (CS2), which is a combustible and poisonous liquid.
If we exchange the hydrogen atoms with chlorine atoms in methane we obtain carbon tetrachloride CCl4. If we exchange the hydrogen atoms with fluoride atoms we obtain fluorocarbon compounds. The Teflon used in our kitchenware is a fluorocarbon resin.
When two carbon atoms each having three hydrogen atoms attached come together, the ethane molecule is formed. As mentioned before chains, branching chains and rings of linked carbon atoms can be formed this way. Some carbon compound's molecules consist of just a few atoms; others contain thousands or even millions. This is one of the main reasons of organic versatility that is behind the scene. Attaching other functional groups to the carbon atoms in the chain increases the versatility of compounds. Some examples of these functional groups that are built up with carbon, oxygen, hydrogen, phosphorus, nitrogen and sulfur coming to mind at first would be the hydroxyl functional group (OH), the carboxyl functional group (COOH), the methyl functional group (CH3), the amino functional group (NH2), the phosphate functional group (PO4), the carbonyl functional group (CO) and the sulfhydryl functional group (SH).
If we exchange one hydrogen atom in methane with a hydroxyl group we obtain methanol, which is an alcohol that damages the optic nerves. To turn methanol into ethanol, which is found in alcoholic beverages we need to add a methyl group to methanol. If we add one oxygen atom or a carboxyl group to ethyl alcohol we will obtain acetic acid (vinegar acid). Adding a nitrogen atom or an amino functional group to acetic acid we obtain amino acids, which are the building blocks of proteins. Looking to these examples we understand that a slight difference in the structure or order of the atoms within a compound can change the whole functionality of that compound. We realize that live systems are fragile and that very sensitive adjustments are made to create the right conditions for the existence of life and that delicate balances are kept to maintain the order of life, which we enjoy so much. Another important fact these examples can prove is that building everything from one thing or building one thing from everything is one of the aspects of creation. This aspect provides us valuable knowledge about creation.
We can explain this matter further with an analogy. To construct a building we need various materials like bricks, cement, wood and iron. Buildings with different architectures and functionalities are constructed with the same materials in different quantities and arrangements. Similarly, this amazing variety of life forms and the order of life on earth are brought to existence with only a few element types (carbon, hydrogen, oxygen, phosphorus, nitrogen and sulfur) which are brought together in different arrangements, representing infinite numbers of different shapes in space.
Life is protected from extinction with buildup and breakdown mechanisms, which change and convert these molecules from one to another.
The popular child game called LEGO is another example that can be used to explain how this infinite variety of life forms is created by a few types of elements. Children can build different objects according to their imagination by using the limited number of plastic pieces in different quantities and arrangements. Just like this, the most merciful has created the amazing nature and every living creature in it by using the limited number of elements in different arrangements and quantities.
Natural forms of pure carbon include graphite, one of the softest minerals known, and diamond, the hardest substance known. The only difference between the two is the structure of the bonds between carbon atoms. Diamond and Graphite, being the same chemical composition, but different crystal structures, are two polymorphs of pure carbon. Another example is aspirin, gasoline and vanillin oil. All three compounds are composed of carbon, oxygen and hydrogen atoms but their properties and usage are completely different. All these examples point to the attribute of creation stating that many things are made from one thing.
Another related topic is isomers. Hydrocarbon variations that differ only in the arrangement of atoms are called isomers. Isomers are very important in biology. The preference for some isomers of molecules that are used in the base metabolism of living beings and biological systems shows us that the existence of life is not without certain intentions and willpower. For example, only the D form isomer of glucose can be used by biological systems. Similarly when the C vitamins are produced synthetically in the lab environment, 50% of those are isomers. Because only one of the isomers is biologically active, our body can use only %50 of the C vitamins we buy from the drug stores.
To stay alive, the human body needs water, air and nutrition from the outside world. It is very important that the nutrition we take has enough elements like iron, zinc ant iodine in it. These elements take place in certain enzymes and molecules, which are important for some proteins and hormones to work properly. For example not having enough iodine in our nutrition can cause an enlargement of the thyroid, which shows up as an abnormal swelling in the neck called a goiter. This illness can be seen more often in mountainous regions where the soil has less iodine because the rainwater washes it away. This reflects on the vegetation and fruits grown in the region and causes the body to not produce enough thyroid hormones. When iodine in nutrition is less than a certain amount it can even slow down the brain development. Similarly iron deficiency causes anemia and zinc deficiency causes growth retardation.
In summary, the magical order and amazing complexity in nature is based on a few molecules, which are arranged in different shapes, orders and in different quantities.
It is one of the miracles of creation that all complex organizations and structures, which even have different specifications, are made from very basic building blocks. The science of complexity (chaos theory, fractal geometries, etc.) has begun to research how God, who is able to make one thing from everything and everything from one thing, has created these astonishing complex beings from very basic and plain molecules. This research to understand how this amazing order and complexity exists will open new doors for the 21'st century science.
- Crawford, M. and Marsh, D. (1989). The Driving Force: Food in Evolution and the Future. Mandarin paperbacks.. Octopus publishing Group. London.
- L. Vlasov & D. Trifonov, 107 Stories About Chemistry, Translator : Nihal Sarier. TUBITAK Populer bilim kitaplari No: 26, ANKARA.