| The American Heritage® Book of English Usage. |
A Practical and Authoritative Guide to Contemporary English. 1996.
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4. Science Terms: Distinctions, Restrictions, and Confusions
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| § 13. catalyst / enzyme / vitamin |
| The word catalyst has been in use since the 1600s and comes from Greek katalusis, “dissolution.” If this etymology seems slightly out of sync for a substance that helps other substances come together and react, consider that the term was first used to describe political situations, especially the breaking apart of governments. By the mid-1800s, though, the political meaning had been rendered obsolete and the term had become part of the lexicon of chemists. Today, a catalyst is a substance that increases the rate of a chemical reaction without undergoing any permanent chemical change itself. Enzymes are a special type of catalyst. They are biochemical in nature, are produced by living organisms, and are usually proteins. Deciding which term you should use depends upon the type of reaction you are describing. If the rate-enhancing compound is influencing the rate of an inorganic reaction, one that involves compounds that do not contain particular groups of atoms called hydrocarbons, the rate-enhancer is called a catalyst. If the agent of quickness is acting on hydrocarbon-containing compounds known as organics, the rate-enhancer is referred to as an enzyme. | 1 |
| Another type of compound that is often seen to behave as a reaction enhancer in the body is the vitamin. Like enzymes, these organic compounds are essential in small quantities for the normal functioning of the body. Unlike enzymes, vitamins are not made by the body; they must be obtained through the foods we eat. Originally thought to be incidental “ingredients” in food, vitamins were dubbed accessory factors. The term vitamin came into use in the early 1900s as a result of the research of Casimir Funk, a Polish-American biochemist. Funk discovered an organic compound that prevented a nerve-damaging illness known as beri-beri and named the substance vitamine, “live amine.” Even though further research has shown that many vitamins do not contain an organic group known as an amine, the name stuck. Research has also shed more light on the pivotal role these nutritional necessities play in metabolism. In the body, nearly all vitamins are converted to coenzymes. In a manner roughly akin to that of an enzyme, a coenzyme acts by changing the location of groups of atoms, moving them from one type of molecule to another. This process, known as a donor-acceptor exchange, is important to the generation and storage of energy needed for the body’s normal growth and functioning. | 2 |
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| The American Heritage® Book of English Usage. Copyright © 1996 by Houghton Mifflin Company. All rights reserved. |
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