Explain noncompetitive inhibitor
A noncompetitive inhibitor can combine with either the free enzyme or the enzyme- substrate complex, interfering both. The most common type of noncompetitive inhibition is affected by the substances that combine with some functional group of the enzyme (outside the catalytic site) that is essential for maintaining the conformation of the enzyme molecule required for its activity. For example, enzymes possessing the essential -SH group are sometimes inhibited by metals like mercury or copper.