Amino acids are organic compounds that contain both an amino (-NH₂) group and a carboxylic acid (-COOH) group, typically attached to the same carbon atom in the α-position. They serve as the fundamental building blocks of proteins and peptides, essential for cellular structure, enzymatic function, and metabolic pathways. In food science and spice chemistry, amino acids contribute significantly to nutritional value, flavor profiles (e.g., glutamic acid for umami), and participate in Maillard browning reactions during cooking. The 20 standard amino acids vary by side-chain R group, influencing properties like hydrophobicity and reactivity. They are critical in human nutrition, with nine classified as essential. Most decompose before boiling and exhibit high water solubility due to zwitterionic forms at physiological pH.