question_answer 119)

  Assertion : Enzymes have active sites that  hold substrate molecule for a chemical reaction.

Answer:

  (D) Correct reason. Drugs compete with natural substrate by attaching by weak bonds (such as ionic bonding, H-bonding, van der Waals interaction, etc.) to the active site of the enzyme. Reason : Drugs compete with natural substrate by attaching covalendy to the active site of enzyme.