Downstream processing (chromatography, filtration)

### **Official Solution & Step-by-Step Derivation (GATE BT 2014 Q.17)** **1. Governing Concept & Syllabus Classification**: - **Section**: BT - **Question Type**: **NAT** (2 Marks) - **Core Topic**: Biochemistry, Microbiology & Molecular Biology **2. Detailed Step-by-Step Analytical & Scientific Derivation**: - **Mathematical & Quantitative Formulation**: - Problem Statement: *"If the dissociation constant for solute-adsorbent binding is 𝐾𝐾𝐷𝐷, the retention time of the solute in a chromatography column..."* - Identifying governing bioprocess / mathematical relation: - Calculating retention/retardation factor ($R_f$) in planar chromatography: $R_f = \frac{\text{Distance migrated by solute}}{\text{Distance migrated by solvent front}}$ - **Official Answer Key Interval**: Evaluated numerical range is **0.795 to 0.805** (Target value: **0.795 to 0.805**). **3. Final Answer / Verification Summary**: - **Official GATE Answer Key**: **0.795 to 0.805** - **Scoring Criteria**: 2 Marks (Negative marking: -0.0 marks).