<prompt> In the Krebs cycle, Malonate competitively inhibitsIsocitrate dehydrogenaseSuccinate thiokinaseSuccinate dehydrogenasea-Ketoglutarate dehydrogenase  <response>: The first dehydrogenation reaction, forming fumarate, is catalyzed by succinate dehydrogenase, which is bound to the inner surface of the inner mitochondrial membrane. The enzyme contains FAD and iron-sulfur Fe-S protein, and directly reduces ubiquinone in the electron transpo chain. This is inhibited by Malonate Reference: Harper; 30th edition; Page no: 163 