Timmons, Rosette (2012) Vitamins important source of nutrition. The English Press, Delhi, India. ISBN 9788132345503
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Abstract
A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. In other words, an organic chemical compound (or related set of compounds) is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Thus, the term is conditional both on the circumstances and on the particular organism. For example, ascorbic acid (vitamin C) is a vitamin for humans, but not for most other animals, and biotin and vitamin D are required in the human diet only in certain circumstances. By convention, the term vitamin does not include other essential nutrients such as dietary minerals, essential fatty acids, or essential amino acids (which are needed in larger amounts than vitamins), nor does it encompass the large number of other nutrients that promote health but are otherwise required less often. Thirteen vitamins are presently universally recognized. Vitamins are classified by their biological and chemical activity, not their structure. Thus, each "vitamin" refers to a number of vitamer compounds that all show the biological activity associated with a particular vitamin. Such a set of chemicals is grouped under an alphabetized vitamin "generic descriptor" title, such as "vitamin A", which includes the compounds retinal, retinol, and four known carotenoids. Vitamers by definition are convertible to the active form of the vitamin in the body, and are sometimes inter convertible to one another, as well. Vitamins have diverse biochemical functions. Some have hormone-like functions as regulators of mineral metabolism (eg, vitamin D), or regulators of cell and tissue growth and differentiation (eg, some forms of vitamin A) Others function as antioxidants (e.g., vitamin E and sometimes vitamin C) . The largest number of vitamins (e.g. B complex vitamins) function as precursors for enuryme cofactors, that help enzymes in their work as catalysts in metabolism. In this role, vitamins may be tightly bound to enzymes as part of prosthetic groups: For example, biotin is part of enzymes involved in making fatty acids
| Item Type: | Book |
|---|---|
| Subjects: | Q Science > QP Physiology |
| Divisions: | Electronic Books |
| Depositing User: | Esam @ Hisham Muhammad |
| Date Deposited: | 12 Feb 2023 06:48 |
| Last Modified: | 12 Feb 2023 06:48 |
| URI: | http://odlsystem2.utm.my/id/eprint/3984 |
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