CARBON - A UNIQUE CHEMICAL ELEMENT
Anyone who studies or just observes the natural world must be impressed by its immense variety. In outer space, here on earth, within our bodies, and all around us, both the inanimate creation and the living world display variety and beauty everywhere, and thereby reflect the glory and wisdom of the Creator. Nothing that God does is ever dull or monotonous.
Just think of the millions of different substances all around us - from paper to plastics, from chalk to cheese, from wood to stone, from water to petrol, from oxygen to steel, from vitamin C to chlorophyll - the list of materials we are familiar with is practically endless. Yet all of them are made from less than ninety different elements, primary substances into which every one could eventually be broken down. In fact most familiar materials are made from only about twenty elements. The commonest elements on earth are first oxygen, then silicon, aluminium, and iron. The important ones for life are carbon, hydrogen, nitrogen and oxygen.
The chemical elements
These primary chemical elements are the basic materials from which everything is made. God designed and made each element with its own kind of atom, different from every other element, so that they could combine with each other in specific ways to produce the millions of compounds we now recognise. Thus, oxygen is an element, but combined with silicon and aluminium it makes stone, combined with calcium and carbon it makes chalk, combined with hydrogen it is water, combined with carbon and hydrogen it makes wood and chlorophyll and many plastics plus a huge number of other substances.
Chemistry is the science which studies the composition and properties of all materials and tries to explain why they behave in certain ways by examining their smallest particles, which are called molecules. Molecules are collections of atoms bonded to each other, sometimes just a few atoms stuck together as in the case of water, or carbon dioxide, or methane, sometimes very large numbers of atoms as in chlorophyll, or proteins, or plastics (often called polymers). Molecules have different shapes and sizes and properties, and most are smaller than a millionth of a centimetre. Chemistry reveals God's handiwork at this submicroscopic level.
The different atoms which make up molecules each have their own unique substructure. Each atom contains a certain number of tinier particles called protons, neutrons, and electrons. The manner in which these are arranged is another marvel, researched and discovered by scientists, not yet completely understood, but designed and built by God. The number of electrons at the outside of an atom decides how it can make chemical bonds to its neighbours.
Atomic and molecular architecture proclaims the wisdom and glory of God. The Lord Jesus said one day, "If these should hold their peace, the stones would immediately cry out" (Lk 19.40). Each atom and molecule in the stones, or in anything else, does cry out, to those who are willing to listen, an eloquent testimony to its Maker.
Carbon the basis of life
Of all the elements, one is special and unique, the element carbon. It is the one from which the structures of all living things are made. Because of this, the study of carbon compounds has traditionally been called organic chemistry. Carbon compounds are much more numerous than the compounds of any other element, and most of these are found in living things.
All living organisms are made up of compounds of carbon bonded to hydrogen, oxygen, nitrogen and less frequently, sulphur. From these few elements, all life forms have been built up and their metabolisms function. It is truly amazing that so few elements can produce such variety, and produce it in the conditions which support life. Thus, in addition to smaller molecules like those of carbon dioxide, water, ammonia, and amino acids, there are very large molecules, such as those of carbohydrates, proteins, fats, and oils, and within each class thousands upon thousands of variations in molecular structure. It is this diverse range of substances which enables life forms to have such variety.
Carbon is the only element which can form such a wide range of different compounds. Each atom can form four bonds with atoms of other elements or with other carbon atoms, and these bonds can be single, double, or triple. This opens up endless possibilities for carbon making different molecules of almost any size and three dimensional shape. The element most like carbon is silicon, but it cannot make bonds like these to any significant extent. Clearly, God designed and made the carbon atom to suit the special requirements of life.
Carbon compounds
The processes which sustain life are very complex but also very efficient. Think, for example, of the intake and digestion of foodstuffs, repair of damaged tissue, transport of nutrients, breathing to provide oxygen which is transported in the blood, producing energy for muscle action or for complex functions within cells.
For all this to happen, the substances involved need to be able to undergo changes (react) at the temperatures at which life exists. If at those temperatures they were too stable, they would not be usable, and if they were too unstable they would change too quickly before they could do their job or reach their target. It is a fascinating fact that at just the temperatures where life thrives, those very compounds of carbon possess this correct, intermediate stability. The properties of the compounds, the strength of the chemical bonds within their molecules, match their usefulness at just the required temperatures by coincidence? No, by design!
Notice how all this fits into the overall picture. Life needs a stable temperature in the 5 to 40 degrees C range. This is where
- the relevant carbon compounds can react;
- the necessary water is a liquid;
- the earth's surface temperature lies.
We have noted already how this temperature is achieved by the sun's heating effect moderated by the effect of the atmosphere and by its distance away from us. That distance in turn has been determined by the mass of the planet. There were no afterthoughts, accidental changes, or evolving conditions to produce life. It is all one grand design put into effect by our faithful Creator for the benefit of His creatures! From the pattern of the electrons in the invisibly tiny carbon atom to the place of planet earth in the magnificently great solar system it all reflects the manifold wisdom of God.
The molecules of life
Our bodies contain about 100 million million cells, each about two hundredths of a millimetre in size. Each has its own function - skin, brain, muscle, blood and so on. Each cell has a similar structure and carries all the information needed to perform many complex tasks, the most important of which is to replicate itself.
Cells can be compared to tiny computers, perfectly designed to run on biologically coded materials to produce biological results. The information is stored in the nucleus of the cell in a key substance called DNA (deoxyribonucleic acid) which stores data more efficiently and compactly than any other known system (would you expect anything else from the Creator?). It has been calculated that the information in about a million million books could be stored in a sample of DNA the size of a pinhead. The structure and function of the DNA molecule is truly astounding.
Alternatively, a cell can be compared to a miniature factory, operating according to specified rules, using efficient transporters of energy and materials, to produce certain chemical compounds. The most important of these are the proteins, synthesised from their building blocks, made exactly as the organism needs them. Millions of different molecules could be made from these raw materials, but only one will have the correct size, three dimensional shape, and reactivity for its end use. The complex processes in the cell (factory) select just the one that is needed, with no unfriendly by-products and no faulty goods! The component carbon, hydrogen, oxygen and nitrogen atoms all fit together according to the design of the Creator as coded into the DNA in each cell.
Proteins do an amazing variety of jobs. They are structural tissue builders, catalysts (enzymes) for reactions, messengers and receptors of information, defenders against toxins, to mention only a few. Their molecules are all different and distinctly folded or coiled, held in place by weak bonds and by interaction with their watery environment, giving each the precise three dimensional shape which is critical to its function.
Central to all this is the unique carbon atom a key part of the Master plan to give the world its variety and beauty, its form and function. "That it all works, and works so well, is nothing short of miraculous."1
To be continued.
1 From a secular textbook: General, Organic and Biological Chemistry by DM Feigl & JW Hill.