Reversible Inhibition

Enzymes are regulated in a variety of Reversible inhibition, which are forms of noncovalent mechanisms. These reversible inhibition methods come in Competitive, uncompetitive, noncompetitive and mixed forms. Competitive inhibition competes for the active site of the enzyme. When the inhibitor binds to the site, it blocks subtrate binding and thus activation of the enzyme activity. This may be overcome with a higher concentration of substrate. the Vmax of the enzyme is unchanged by this, though this increases the Km. Uncompetitive inhibition is when an inhibitor binds to a spot other than the active site. This only occurs when a substrate is already bound to the enzyme, but it will block further enzyme activity. This method lowers both Vmax and Km. Noncompetitive inhibition and mixed inhibition both bind whether there is a substrate bound to the enzyme or not. Thus, this cannot be overcame with a higher substrate concentration. What seperates these two methods is that during noncompetitive inhibition, Vmax will decrease, but Km will be uneffected. Mixed inhibition will decrease the Vmax as well but Km may either rase or lower depending on certain conditions.