Explain5 marksChallenge
An enzyme from a thermophilic bacterium was immobilised in alginate beads to study its activity at different temperatures. The initial rate of reaction was measured at each temperature under conditions of saturating substrate concentration. The experiment was repeated in the presence of a fixed concentration of a reversible inhibitor. The results are shown in the table below.
| Temperature (°C) | Rate without inhibitor (μmol min⁻¹) | Rate with inhibitor (μmol min⁻¹) |
|---|---|---|
| 10 | 2 | 1 |
| 20 | 5 | 2.5 |
| 30 | 12 | 6 |
| 40 | 25 | 12.5 |
| 50 | 35 | 17.5 |
| 60 | 20 | 10 |
| 70 | 5 | 2.5 |
Explain the effect of temperature on the rate of this enzyme-catalysed reaction, and explain the effect of the reversible inhibitor on the Vmax and Km of the enzyme. Use the data to support your answer.