Definition: The term "ammocete" refers to an amino acid that contains a phenylalanine (Cys) residue at its 3 position, often used in the context of the amino acid methionine (Met) as part of the methyl group, which is commonly known as a "methylamine." The name "ammocete" comes from the term "ammonia," which means ammonia. Ammoniacs are compounds containing one or more nitrogen atoms and have the formula NH2. The 3-position of an amino acid is where it attaches to its corresponding amino group. The methyl group in ammocets consists of a phenylalanine (Cys) residue at the 3 position, which is often known as the "methylamine" because it has the chemical name methylamine. Methionines are commonly used in the synthesis of medicines and in various biochemical processes, including protein synthesis. They are also found in foods such as soy milk and milk products, as well as in animal sources like meat, cheese, and eggs. In summary, ammocets contain a phenylalanine (Cys) residue at its 3 position, commonly known as the methylamine because it has the chemical name methylamine. They are commonly used in the synthesis of medicines and in various biochemical processes.