Anitgen binding site on an antibody comprises of | Agrigyan

• Buffering Capacity of Bovine Milk:
• Principal Buffering Salts:
• Milk exhibits maximum buffering capacity around $\text{pH } 5.2$ and $\text{pH } 6.6$.
• Phosphates (colloidal calcium phosphate associated with casein micelles and soluble inorganic orthophosphates $\text{HPO}_4^{2-} / \text{H}_2\text{PO}_4^-$) provide the predominant mineral buffering power across the physiological pH range.
• Citrates and casein carboxyl/amino residues provide supplementary buffering.
• Conclusion: Phosphates (Option 4).

Correct option: (4) Phosphates

• Thermal Conditioning of Milk ($90^\circ\text{C}$ for 10 min):
• Heat-Induced Whey Protein-Casein Complexation:
• High-temperature preheating ($90^\circ\text{C} / 10\text{ min}$) denatures globular whey proteins, primarily $\beta$-lactoglobulin, exposing free sulfhydryl groups.
• Denatured $\beta$-lactoglobulin forms disulfide-linked covalent complexes with $\kappa$-casein on the micelle surface, preventing micellar heat coagulation and substantially increasing heat stability during subsequent sterilization.
• Conclusion: Increase in heat stability (Option 3).

Correct option: (3) Increase in heat stability

• Function and Positioning of Guard Columns in HPLC:
• Instrumental Configuration:
• Installed between the sample injector and the analytical column.
• Packed with identical stationary phase material in a short ($1 - 2\text{ cm}$) cartridge.
• Traps particulate debris, insoluble precipitates, and irreversibly adsorbing matrix components, shielding the expensive analytical column from column fouling and loss of efficiency.
• Conclusion: Between the injector and analytical column (Option 1).

Correct option: (1) Between the injector and analytical column

• Reaction Kinetics of Maillard Browning Color Formation:
• Zero-Order Kinetic Modeling:
• In both model sugar-amino acid mixtures and complex food products (milk powder, evaporated milk), the optical accumulation of brown melanoidin pigment ($\Delta A_{420}$) during continuous heating follows zero-order kinetics:

• Conclusion: Zero order kinetics (Option 4).

Correct option: (4) Zero order kinetics,