Amino acid | Definition, Structure, & Facts | Britannica
4 天之前 · An amino acid is an organic molecule that is made up of a basic amino group (−NH 2), an acidic carboxyl group (−COOH), and an organic R group (or side chain) that is unique to …
Protein - Amino Acids, Structure, Function | Britannica
2025年1月14日 · Protein - Amino Acids, Structure, Function: The common property of all proteins is that they consist of long chains of α-amino (alpha amino) acids. The α-amino acids are so …
Alanine | Amino Acid, Protein, Metabolism | Britannica
alanine, either of two amino acids, one of which, L-alanine, or alpha-alanine (α-alanine), is a constituent of proteins. An especially rich source of L-alanine is silk fibroin, from which the …
Nucleic acid | Definition, Function, Structure, & Types | Britannica
2024年11月22日 · Nucleic acids are naturally occurring chemical compounds that serve as the primary information-carrying molecules in cells. They play an especially important role in …
Acid | Definition, Examples, Types, Uses, & Facts | Britannica
2025年1月11日 · What is an amino acid? What are the 20 amino acid building blocks of proteins? What is the difference between standard and nonstandard amino acids? What are some …
Valine | Amino Acid, Protein, Metabolism | Britannica
valine, an amino acid obtained by hydrolysis of proteins and first isolated by the German chemist Emil Fischer (1901) from casein. It is one of several so-called essential amino acids for fowl …
Creatine | Definition & Applications | Britannica
5 天之前 · What is an amino acid? What are the 20 amino acid building blocks of proteins? What is the difference between standard and nonstandard amino acids? What are some industrial …
Fatty acid | Definition, Structure, Functions, Properties, & Examples ...
2025年1月4日 · Both stearic acid (a fatty acid) and phosphatidylcholine (a phospholipid) are composed of chemical groups that form polar “heads” and nonpolar “tails.” The polar heads …
Tryptophan | Amino Acid, Protein, Metabolism | Britannica
2025年1月2日 · tryptophan, an amino acid that is nutritionally important and occurs in small amounts in proteins. It is an essential amino acid, meaning that humans and certain other …
Structure and properties of amino acids | Britannica
amino acid, Any of a class of organic compounds in which a carbon atom has bonds to an amino group (―NH2), a carboxyl group (―COOH), a hydrogen atom (―H), and an organic side …