What is it: A Process Control Plan (PCP) is a summary of defect prevention and reactive detection techniques. The overall intent of the PCP is to control the product characteristics and the associated process variables to ensure capability (around the identified target or nominal) and stability of the product over time.
Various compounds can reduce the activity of enzymes. They may act in a variety of different ways, and indeed may be reversible or irreversible inhibitors of the enzyme. An irreversible inhibitor causes covalent modification of the enzyme, so that its activity is permanently reduced.
A competitive inhibitor could bind to an allosteric site of the free enzyme and prevent substrate binding, as long as it does not bind to the allosteric site when the substrate is bound. For example, strychnine acts as an allosteric inhibitor of the glycine receptor in the mammalian spinal cord and brain stem.