Chemical Elements Essential to Life

Science has recorded the existence of more than 110 elements, and further elements may be synthesized in the future. However, the majority of these elements are not essential to life. Although the synthesis of such elements as rutherfordium and roentgenium is a remarkable scientific achievement, life has prospered for several millennia without them. Even the majority of naturally occurring elements make no contribution to physiological processes. In fact, some are harmful. We do not want to ingest too much lead, mercury, uranium, or thorium. A little argon or helium won’t hurt you, but they won’t help you either. We could even live without gold, though the misers of the world would vociferously object.

According to “Biology” by Neil Campbell and others, about 25 elements are essential to life. Prominent among these essential elements is carbon. Chains and rings of carbon atoms form the backbone of every organic molecule. A significant percentage of all your tissues is carbon. If you examine the chemical formula of such amino acids as leucine and alanine, you will notice that carbon occupies a prominent position in their molecular structure.

However, an organism needs more than carbon to survive. Many of our important foods are carbohydrates, in which hydrogen and oxygen are united with carbon. Cellulose, an important constituent in plant anatomy, is also composed of carbon, hydrogen, and oxygen. The same is true of chitin, which occurs in the exoskeletons of insects and other organisms. The fats that provide extra weight to the human body also consist of carbon, hydrogen, and oxygen atoms.

In other organic molecules, these three elements are united with nitrogen. Amino acids are a good example. They all contain an amino group, which consists of nitrogen and hydrogen, and the -COOH group, which occurs in all organic acids. Since amino acids are the building blocks of proteins, all the proteins in your body tissues contain these four elements.

In addition, the amino acids cysteine and methionine contain sulfur. As a result, proteins generally have a small amount of sulfur in their composition.

DNA and RNA, the nucleic acids, contain not only carbon, hydrogen, oxygen, and nitrogen, but also phosphorus. In addition, phosphorus is a constituent of such important molecules as adenosine triphosphate (ATP), which provides your cells with energy. Your cell membranes contain phospholipids, which are amalgamations of phosphorus and fat.

Iron is necessary for healthy blood. As a constituent of the hemoglobin molecule, iron temporarily unites with oxygen when this life-giving gas is transported from the lungs to the cells.

We would have trouble finding something to eat if there were no magnesium in the world. A magnesium atom lies at the center of every chlorophyll atom. Without magnesium, chlorophyll could not make the food necessary for plant growth. The plants would die, and plant-eating animals would starve to death. The carnivorous animals could subsist on one another for a while, but eventually they too die of starvation.

Calcium is an important constituent in bone tissue. Moreover, calcium circulates in the blood stream. Two hormones see to it that the blood has the correct amount of calcium at all times. When there is too much, the thyroid gland secretes a hormone called calcitonin, which lowers calcium levels in the blood by depositing it on the bones of the body. When there is not enough calcium, the parathyroid glands secrete parathyroid hormone, which induces the uptake of dietary calcium from the intestines, or else removes some calcium from the bones.

Various elements serve as electrolytes that circulate in the blood stream. When people sweat on a hot day, they tend to lose electrolytes. They can regain some of these by ingesting a little salt. Salt is a compound that contains sodium and chlorine. Another important electrolyte is potassium.

In order to function properly, the thyroid gland needs a little iodine. An iodine deficiency may result in a goiter.

Several other elements are present in the human body in minute quantities. They are called trace elements, and their importance is gradually being learned. According to “Biology” by Neil Campbell and others, the following are trace elements in the human body: boron, chromium, cobalt, copper, fluorine, manganese, molybdenum, selenium, silicon, tin, vanadium, and zinc. Iron and iodine, which I have treated separately, are also listed as trace elements, since they take up less than 0.01% of the weight of the human body.

The sources of most of this information are my own memory and my expertise in the field. For my knowledge, I am indebted to my science courses at Northwestern College and intensive independent study in the field. I am also indebted to a professor in Houston, Texas, for the explanation of how the body regulates calcium level in the blood. I cannot remember his name because I heard his lecture many years ago.

Reference:

“Biology” by Neil A. Campbell, Jane B. Reece, and Lawrence G. Mitchell