Classification of amino acids based on structure; aromatic, aliphatic, acidic, basic, sulfur containing, branched chain, essential and non-essential. Globular& Fibrous protein, denaturation, Hierarchy in structure (primary, secondary, tertiary), different protein hydrolysis. Digestibility, color reactions of proteins and amino acids. Amino acid analysis, protein digestibility corrected amino acid score. Rheological properties of protein- solubility, viscosity, gelling, surfactants.