Using Table 18.3, name the α-amino acids that (a) contain an aromatic ring, (b) contain sulfur, (c) are alcohols, and (d) have alkyl-group side chains.

Verified step by step guidance

1. Identify the α-amino acids that contain an aromatic ring. These amino acids have a benzene ring or a derivative of a benzene ring in their side chain.
2. Look for α-amino acids that contain sulfur in their side chain. These amino acids will typically have sulfur atoms directly bonded to carbon or as part of a thiol or thioether group.
3. Identify the α-amino acids that are classified as alcohols. These amino acids will have a hydroxyl group (-OH) attached to their side chain.
4. Determine the α-amino acids that have alkyl-group side chains. These side chains are composed solely of carbon and hydrogen atoms arranged in a branched or linear chain.
5. Refer to Table 18.3 or a similar comprehensive chart of amino acids to match these characteristics with specific amino acids.

Key Concepts

Amino Acid Structure

Amino acids are organic compounds that serve as the building blocks of proteins. Each amino acid has a central carbon atom bonded to an amino group, a carboxyl group, a hydrogen atom, and a variable side chain (R group) that determines its properties. Understanding the structure of amino acids is essential for identifying their classifications based on functional groups.

Aromatic Amino Acids

Aromatic amino acids contain an aromatic ring in their side chain, which contributes to their unique chemical properties. The three primary aromatic amino acids are phenylalanine, tyrosine, and tryptophan. Recognizing these amino acids is crucial for answering questions related to their specific characteristics and functions in proteins.

Functional Groups in Amino Acids

Functional groups are specific groups of atoms within molecules that determine the chemical reactivity and properties of those molecules. In amino acids, common functional groups include hydroxyl (-OH) for alcohols and thiol (-SH) for sulfur-containing amino acids. Identifying these groups helps categorize amino acids based on their chemical behavior and biological roles.