Structural organization and functional diversity of proteins, Protein synthesis, Protein export and secretion. Structure and physiological importance of lipo-proteins and glyco-proteins, collagen & antibodies. Enzymes as biological catalyst. Nomenclature and classification of major classes of enzymes. Nature, mechanism & specificity of enzymes. Concept of activation energy. Introduction to enzyme kinetics - Km, Vmax . Effect of substrate, enzyme, temperature, pH and salt concentration on enzyme activity. Enzyme models - Lock & Key and Induced fit. Enzyme inhibitors.