Melonate inhibits the growth of pathogenic bacteria by inhibiting the activity of

Solution & Explanation

Answer: (A) Succinic dehydrogenase. Solution: This is the classic NCERT example of competitive inhibition. Malonate (‘Melonate’) closely resembles the substrate succinate in molecular structure and competes with it for the active site of succinic dehydrogenase, thereby inhibiting the enzyme. Such competitive inhibitors are used to control bacterial pathogens, which is why malonate inhibits pathogen growth. NCERT Reference: Ch 9, p.117, line ~10 — "inhibition of succinic dehydrogenase by malonate which closely resembles the substrate succinate in structure. Such competitive inhibitors are often used in the control of bacterial pathogens."