4 public questions tagged with this topic.
Restriction enzymes recognize specific palindromic sequences in DNA and cut at those sites.
Ref: NCERT Class 12 Biology Chapter 9: Biotechnology: Principles and Processes Tools - Restriction Enzymes - Molecular Scissors
Type II restriction enzymes recognize specific palindromic hexamers and cut within them producing defined ends. Sequence 5'-GATATC-3' contains central ATAT palindrome recognized by EcoRV, which cuts between T and A on both strands generating blunt ends, unlike BamHI recognizing GGATCC or EcoRI recognizing GAATTC which produce sticky overhangs. EcoRV is frequently used to create blunt cloning junctions and for physical mapping studies. Memorizing common hexameric sites as per NCERT and typical molecular biology laboratory practice is crucial for predicting fragment ends and designing compatible cloning strategies efficiently.
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.
Kcat / Km is the accurate response regarding enzymatic activity or regulation described in this question. Enzymes are biological catalysts that accelerate reactions by lowering activation energy through specific substrate binding and transition state stabilization. In the context of Enzyme Kinetics, Kcat / Km plays a specific catalytic or regulatory role determined by its active site configuration and mechanism of action. The other options (Km / Vmax, Kcat × Km, and Km × Vmax) are either different enzymes with distinct substrate specificities, act through different mechanisms, or are involved in separate metabolic pathways.
Ref: Lehninger Principles of Biochemistry, Nelson & Cox, 8th Ed., Ch. 6
The shape of the active site is the accurate response regarding enzymatic activity or regulation described in this question. Enzymes are biological catalysts that accelerate reactions by lowering activation energy through specific substrate binding and transition state stabilization. In the context of Enzyme Kinetics, The shape of the active site plays a specific catalytic or regulatory role determined by its active site configuration and mechanism of action. The other options (The molecular weight of the enzyme, The hydrophobicity of the enzyme, and The presence of cofactors) are either different enzymes with distinct substrate specificities, act through different mechanisms, or are involved in separate metabolic pathways.
Ref: Lehninger Principles of Biochemistry, Nelson & Cox, 8th Ed., Ch. 6
