Fiber is an important component of your diet. From helping to keep your digestive tract functioning properly to helping to bind toxins and keep them from entering the bloodstream, fiber serves a number of important biological functions. Despite the fact that it's a very large molecule, it's made up of only three different elements.
Fiber
There are actually several different types of fiber in the human diet, falling into the two distinct categories of soluble and insoluble fiber. However, the colloquial term "fiber" almost always refers to the compound cellulose, which is insoluble fiber. You consume cellulose any time you eat fruits, vegetables or whole grains. While you can't digest cellulose, explains Dr. Lauralee Sherwood in her book "Human Physiology," it serves many valuable functions in the body, including decreasing the risk of constipation.
Carbon
Organic molecules -- the molecules of life -- are carbon based. This means that regardless of the other elements incorporated into an organic molecule, the molecule's general shape, or skeleton, is made up of carbon. Cellulose is no exception. Cellulose actually consists of a long chain of smaller molecules chemically bonded to one another. Each of these smaller molecules, called glucose, contains six carbon atoms, explain Drs. Reginald Garrett and Charles Grisham in their book "Biochemistry."
Hydrogen
While carbon forms the skeleton of cellulose, hydrogen is the most prevalent element in terms of the sheer number of atoms of that element present. There are nearly twice as many hydrogen atoms as carbon atoms in a cellulose molecule, but because hydrogen atoms are so small, they don't much affect the overall shape of the cellulose molecule. The hydrogen atoms in cellulose contribute to some extent to its chemical activity; they help bind individual units of glucose together, for instance.
Oxygen
Most of fiber's reactivity comes from the presence of many oxygen atoms. There are nearly as many oxygen atoms per cellulose molecule as there are carbon atoms; each glucose unit contains six oxygen atoms, but when two glucose units bind to one another to form part of the cellulose chain, they lose an oxygen atom. A fully formed cellulose chain has five oxygen atoms per glucose unit. The oxygen atoms are instrumental in forming the bonds between adjacent glucose units.
References
- "Human Physiology"; Lauralee Sherwood, Ph.D.; 2004
- "Biochemistry"; Reginald Garrett, Ph.D. and Charles Grisham, Ph.D.; 2007
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