Amino Acids


The Biology Project > Biochemistry > The Chemistry of Amino Acids
Basic Structure of Amino Acids Acidic & Amides Aliphatic Aromatic Basic Cyclic Hydroxyl Sulfur-Containing Gly to Leu Asp to Gln Ala to Trp Test yourself Structure & Chemistry ID Structures Letter Codes Author of 1 letter codes Dr. M.O. Dayhoff	The Chemistry of Amino Acids Introduction Essential amino acids Why learn this? Amino acids play central roles both as building blocks of proteins and as intermediates in metabolism. The 20 amino acids that are found within proteins convey a vast array of chemical versatility. The precise amino acid content, and the sequence of those amino acids, of a specific protein, is determined by the sequence of the bases in the gene that encodes that protein. The chemical properties of the amino acids of proteins determine the biological activity of the protein. Proteins not only catalyze all (or most) of the reactions in living cells, they control virtually all cellular process. In addition, proteins contain within their amino acid sequences the necessary information to determine how that protein will fold into a three dimensional structure, and the stability of the resulting structure. The field of protein folding and stability has been a critically important area of research for years, and remains today one of the great unsolved mysteries. It is, however, being actively investigated, and progress is being made every day. As we learn about amino acids, it is important to keep in mind that one of the more important reasons to understand amino acid structure and properties is to be able to understand protein structure and properties. We will see that the vastly complex characteristics of even a small, relatively simple, protein are a composite of the properties of the amino acids which comprise the protein. Top Essential amino acids Humans can produce 10 of the 20 amino acids. The others must be supplied in the food. Failure to obtain enough of even 1 of the 10 essential amino acids, those that we cannot make, results in degradation of the body's proteins—muscle and so forth—to obtain the one amino acid that is needed. Unlike fat and starch, the human body does not store excess amino acids for later use—the amino acids must be in the food every day. The 10 amino acids that we can produce are alanine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine and tyrosine. Tyrosine is produced from phenylalanine, so if the diet is deficient in phenylalanine, tyrosine will be required as well. The essential amino acids are arginine (required for the young, but not for adults), histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. These amino acids are required in the diet. Plants, of course, must be able to make all the amino acids. Humans, on the other hand, do not have all the the enzymes required for the biosynthesis of all of the amino acids. Why learn these structures and properties? It is critical that all students of the life sciences know well the structure and chemistry of the amino acids and other building blocks of biological molecules. Otherwise, it is impossible to think or talk sensibly about proteins and enzymes, or the nucleic acids. Top	Amino Acids Alanine Arginine Asparagine Aspartic acid Cysteine Glutamic acid Glutamine Glycine Histidine Isoleucine Leucine Lysine Methionine Phenylalanine Proline Serine Threonine Tryptophan Tyrosine Valine Atoms in Amino Acids
The Biology Project > Biochemistry > The Chemistry of Amino Acids CREDITS
	The Biology Project Department of Biochemistry and Molecular Biophysics University of Arizona September 30, 2003 Contact the Development Team http://www.biology.arizona.edu All contents copyright © 2003. All rights reserved.

The Chemistry of Amino Acids