Succinic dehydrogenase is an enzyme that causes the substrate, succinate, to breakdown into fumarate. Malonate is a substance that resembles succinate and inhibits the activity of succinic dehydrogenase.
(i) State the type of inhibition of succinic dehydrogenase by malonate.
(ii) Explain how this type of inhibition affects the activity of the enzyme.
(i) The type of inhibition of succinic dehydrogenase by malonate is competitive inhibition.
(ii) The inhibitor competes with the substrate for the active sites of enzyme molecules as it has a structure similar to the substrate that allows it to combine with the active site, preventing any substrate molecule from occupying that site. This reduces the rate of the reaction since, the substrate can only use the enzyme molecules that are not occupied by the inhibitor, resulting in the same quantity of product being formed at a slower rate.