Link to illustrated discussion of the citric acid cycle. If one adds malonic acid to cells, or to a test tube mixture of succinic acid and the enzyme, the action of the enzyme is strongly inhibited. But there is no oxidation so no speedy release of products. The inhibition is called competitive because if you increase the ratio of succinic to malonic acid in the mixture, you will gradually restore the rate of catalysis. Link to a quantitative treatment of competitive inhibition.
Many enzymes require the presence of an additional, nonprotein, cofactor.
Some cofactors are small organic molecules called coenzymes . Others bind more loosely and, in fact, may bind only transiently to the enzyme as it performs its catalytic act. The enzyme is antibacterial because it degrades the polysaccharide that is found in the cell walls of many bacteria. It does this by catalyzing the insertion of a water molecule at the position indicated by the red arrow. This hydrolysis breaks the chain at that point.