<prompt> A competitive inhibitor of an enzyme will?Alter the Vmax of the reactionBind to the same site as the substrateDecrease the apparent Km for the substrateDecrease the turnover number  <response>: Substances that reduce the activity of an enzyme are called inhibitors. Reversible inhibitors bind to an enzyme but rapidly dissociate from it . There are several types of reversible inhibitors: Competitive inhibitors usually resemble the substrate and compete with it for binding at the active site. Thus, increasing the concentration of substrate will decrease the percent inhibition of the enzyme. The Vmax is unchanged, but the Km is increased. A noncompetitive inhibitor binds with equal affinity to both enzyme and enzyme-substrate complex. This binding leads to a distoion of the substrate binding site, so new substrate cannot bind andor the product cannot be released. In this kind of inhibition, the Vmax is decreased choice A, but the Km is not altered. Adding more substrate will not reverse this type of inhibition. This is the equivalent of decreasing the turnover number. An uncompetitive inhibitor does not bind to free enzyme, but binds to the enzyme-substrate complex at a site other than the catalytic site. Once bound by the inhibitor, the enzyme is trapped in the enzyme-substrate complex state until the inhibitor dissociates. In this kind of inhibition, the slope of the reaction which is the ratio KmVmax remains the same, but both Vmax and Km are reduced. Ref: Janson L.W., Tischler M.E. 2012. Chapter 5. Enzymes and Amino AcidProtein Metabolism. In L.W. Janson, M.E. Tischler Eds, The Big Picture: Medical Biochemistry. 