Chemistry - Biomolecules Question with Solution | TestHub

Competitive inhibition:The action of an enzyme may be reduced or inhibited in the presence of a substance that closely resembles the substrate in molecular structure. Such an inhibitor is called a Competitive Inhibitor of that enzyme. Due to its close structural similarity with the substrate, the inhibitor competes with the latter for the substrate-binding site of the enzyme. Consequently, the enzyme cannot participate in catalysing the change of the substrate. As a result the enzyme action declines, e.g, the inhibition of succinic dehydrogenase by malonate, which closely resembles succinate in structure. This may be compared to a lock jammed by a key similar to the original key. Such competitive inhibitors are often used in the control of bacterial pathogens. For instance, sulpha drugs are competitive inhibitors of folic acid synthesis in bacteria as they substitute for p-amino benzoic acid, thus preventing the next step in the synthesis.