|Fiorotto, Marta -|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: April 14, 2008
Publication Date: October 1, 2008
Citation: Fiorotto, M.L. 2008. Protein, Chapter 14. Section III Micronutrients and Macronutrients. In: Kleinman, R.E., editor. Pediatric Nutrition Handbook. 6th edition. Elk Grove Village, IL: The American Academy of Pediatrics Publishers. p. 325-342. Technical Abstract: Proteins are the major structural and functional components of all cells in the body. They are macromolecules that comprise 1 or more chains of amino acids that vary in their sequence and length and are folded into specific 3-dimensional structures. The sizes and conformations of proteins, therefore, are infinitely diverse and complex, and this enables them to serve an extensive variety of functions in the cell. Dietary protein provides the amino acids required for both the synthesis of body proteins and the production of other nitrogenous compounds with important functional roles, such as glutathione, creatine, hemes, nucleotides, hormones, nitric oxide, bile acids, and some neurotransmitters. Amino acids can exist as various stereoisomers in nature. Only the L-amino acids are biologically active and can be incorporated into proteins. Body proteins also can be catabolized and serve as an energy source when energy intake, in particular carbohydrate intake, is inadequate.