4.2 An enzyme has a KM value of 3.5 × 10-3 M and is inhibited by a competitive inhibitor I (KI is 4 × 10-5 M). The substrate concentration is 5 × 10-4 M. 4.2.1 How much of the inhibitor is needed for 65% inhibition? (6) 4.2.2 How much does the substrate concentration have to be increased to reduce the inhibition to 35%?