Amino Acids, Peptides and N-containing/Heterocyclic Compounds

Amino acids, peptides, and nitrogen heterocycles

An α-amino acid contains an amino group and a carboxyl group on the same central carbon, H₂N–CH(R)–COOH. One group can accept H⁺ and the other can donate it, so amino acids are amphoteric and often exist as zwitterions. Condensation between amino acids forms peptide bonds.

Learning goals

• recognize α-amino acids and zwitterions;
• explain amphoteric behaviour;
• form and identify peptide bonds;
• distinguish amines, amides, and N-heterocycles;
• compare pyridine and pyrrole qualitatively.