NEETBotanyBiomolecules (B)
A chemical substance 'X' is often used to control bacterial pathogens because its molecular structure closely resembles that of an essential substrate 'Y'. How does substance 'X' most likely inhibit the enzyme action?
Options
- AIt permanently denatures the enzyme by irreversibly binding to its active site.
- BIt competes directly with the substrate for the active site of the enzyme.
- CIt binds to a site other than the active site, altering the enzyme's three-dimensional shape.
- DIt binds to the product of the reaction, preventing its dissociation from the enzyme complex.
Correct answer
B. It competes directly with the substrate for the active site of the enzyme.
Step-by-step solution
When an inhibitor closely resembles the substrate in its molecular structure, it acts as a competitive inhibitor. Due to this structural similarity, the inhibitor competes with the substrate for the substrate-binding site (active site) of the enzyme. NCERT states that such competitive inhibitors are often used in the control of bacterial pathogens. Competitive inhibitors do not denature the enzyme, nor do they bind to allosteric sites (which is characteristic of non-competitive inhibition) or to the product. Answer