Malonate Succinate Fumarate Succinate dehydrogenase catalyzes the conversion of succinate to fumarate, in the TCA cycle. A double bond is generated between the 2 middle carbons. The carboxyl groups are not changed. Malonate is an effective competitive inhibitor for this reaction because malonate resembles succinate, with 2 carboxyl groups, but it cannot be a substrate with only 1 CH2 group between the carboxyls.
Succinate dehydrogenase catalyzes the conversion of succinate to fumarate, in the TCA cycle. A double bond is generated between the 2 middle carbons. The carboxyl groups are not changed. Malonate is an effective competitive inhibitor for this reaction because malonate resembles succinate, with 2 carboxyl groups, but it cannot be a substrate with only 1 CH2 group between the carboxyls.