enzyme inhibitor

Many foreign substrates inhibit the effect of enzyme catalysis. Some of it is an organic compound (some metal cations) and a few more organic compounds. Both compounds were classified as inhibitors or non-competitive based on its influence on the substrate.
Competitive inhibitors usually have a structure similar to the substrate, so as to compete for the enzyme active site. The concentration of enzyme molecules which effectively reduced so that the reaction rate decreases. The addition of more of the original substrate can overcome the influence of a competitive inhibitor.
Examples of competitive inhibitor is competitive inhibition of succinate dehydrogenase by malonate anion. Succinate dehydrogenase is a class of enzymes that mengkatalisi citric acid and fats in the mitochondria. This enzyme is the release of two or three hydrogen atoms of the succinate, the methylene group (-CH2-). Succinate dehydrogenase is inhibited by malonate of succinic resemble because both have two carboxyl groups-containing ions at pH 7.0, but only differ in the three carbon atoms. However, malonate is not terdehidrogenasi by succinate dehydrogenase, malonate only occupy the enzyme active side and lock it so that it can not work on the substrate normal
Non-competitive inhibitors do not have a structure similar to the substrate and enzyme inhibitor complexes formed at a place outside the enzyme active site. Inhibitors cause changes in the structure of the enzyme substrate so that although the original ": bind to the enzyme, catalysis can not take place. For example, cyanide combines with metal ions such as copper ions of certain enzymes of the cytochrome oxidase enzyme activity was inhibited.