Fish Physiology and Biochemistry- ICAR JRF/SRF 2024

• Affinity Chromatography:
• powerful liquid chromatographic purification technique that separates biological molecules based on highly specific, reversible, non-covalent biological binding interactions.
• specific ligand (e.g., antibody, enzyme substrate, hormone, nucleic acid, histidine-tag binding nickel chelate) is immobilized onto an insoluble chromatographic matrix (agarose/Sepharose).
• Only the target molecule possessing binding affinity binds to the stationary column, while unbound contaminants are washed away. The target is subsequently eluted using a competitive ligand or altered pH/salt.
• nalysis:
• (Separate specific molecules based on a unique binding interaction): Correct.

Correct option: (2) Separate specific molecules based on a unique binding interaction

• Cartilage Proteoglycans and Glycosaminoglycans:
• Cartilage extracellular matrix consists of type II collagen fibrils embedded in a dense proteoglycan gel dominated by aggrecan.
• Aggrecan is heavily decorated with Chondroitin Sulfate—a sulfated glycosaminoglycan (mucopolysaccharide) composed of repeating disaccharide units of glucuronic acid and N-acetylgalactosamine.
• Its high density of negatively charged sulfate ($-SO_3^-$) and carboxyl ($-COO^-$) groups attracts water molecules, creating high swelling turgor pressure that gives cartilage its exceptional compressive stiffness and shock-absorbing resilience.
• nalysis:
• (Chondroitin sulphate): Correct.

Correct option: (4) Chondroitin sulphate

• Antioxidant Action of Catalase:
• Catalase is a tetrameric heme-containing antioxidant enzyme localized predominantly within peroxisomes.
• It catalyzes the rapid, two-electron dismutation of toxic hydrogen peroxide ($H_2O_2$) into harmless water ($H_2O$) and molecular oxygen ($O_2$):

• With one of the highest turnover numbers known ($k_{cat} \approx 40,000,000\text{ s}^{-1}$), it protects cells from oxidative damage caused by reactive oxygen species (ROS).
• nalysis:
• (Catalyzes the breakdown of hydrogen peroxide into water and oxygen): Correct.

Correct option: (1) Catalyzes the breakdown of hydrogen peroxide into water and oxygen