Mcat Practice Questions Study Guide Questions And Correct Answers

Discuss why competitive inhibition can be overcome with increasing substrate concentration but non-competitive inhibition cannot be overcome. {Ans: -Competitive inhibitors are structurally similar to the substrate of an enzyme. This means that in the course of catalyzing reactions the enzyme can bind the inhibitor instead of the substrate. Imagine there are an equal number of inhibitor and substrate molecules. The chance that the enzyme will bind the inhibitor is equal to the chance that it will interact with the substrate. Thus, the rate of catalysis will be decreased, effectively inhibiting the enzyme. However, if the concentration of substrate if 1,000 or 100,000 times greater than the concentration of inhibitor, then the chance the enzyme will randomly interact with the inhibitor instead of the substrate falls dramatically (practically to zero). -Noncompetitive inhibitors do not associate with the enzyme at the active site. Instead, they bind at an allosteric site. When a noncompetitive inhibitor is bound, the enzyme cannot catalyze bind the substrate. Increasing the concentration of substrate will not decrease the likelihood of a noncompetitive inhibitor associating at an allosteric site.}Which of the following is FALSE regarding DNA replication? A . DNA replication requires an RNA primer. B . Nucleoside