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An enzyme-controlled reaction was carried out with no inhibitor, with inhibitor X, and with inhibitor Y. The graph shows the rate of reaction against substrate concentration for each.
One of the inhibitors is competitive and one is non-competitive. Using the graph, deduce which inhibitor, X or Y, is the competitive inhibitor, and give one piece of evidence.
Explain how a competitive inhibitor reduces the rate of reaction.
Explain why increasing the substrate concentration does not return the rate to the uninhibited value for inhibitor Y.