An Enzyme Inhibitor interferes with an enzyme on a temporary or permanent basis causing it to reduce the rate of reaction of an enzyme catalysed reaction.

Nonspecific Inhibitors

  • Non Specific Inhibitors¬† are those that affect all enzymes under the same conditions, this usually is the result of physical or chemical changes causing the enzyme to denature.
  • Examples of Nonspecific Inhibitors:
    • Low/High temperature
    • Extreme Low/High pH

Competitive Inhibitors

  • Competitive Inhibitors compete with substrates for positions at the enzymes active site.
  • They usually have a shape close to the substrate. The inhibitor blocks the site for other enzymes to attach.
  • The result slows down the reaction, rather than stops it.

Non Competitive Inhibitors

  • Non-competitive inhibitors do not compete with the substrate, it binds to the allosteric site.
  • As a result the active site of the enzyme changes.
  • Thus, the substrate cannot bond to it. If the non-competitive inhibitor releases, then the enzyme restores back to normal.
  • It slows the reaction down rather than stops it.