Describe5 marksStandard
A student investigated the effect of substrate concentration on the activity of the enzyme dipeptidase from the thermophilic bacterium Bacillus caldox. The enzyme catalyses the hydrolysis of a synthetic dipeptide, X. The initial rate of reaction was measured at each substrate concentration. The results are shown in the table below.
| Substrate concentration / mmol dm⁻³ | Initial rate / arbitrary units |
|---|---|
| 0.0 | 0 |
| 0.1 | 2.1 |
| 0.2 | 3.8 |
| 0.4 | 5.5 |
| 0.8 | 6.8 |
| 1.6 | 7.5 |
| 3.2 | 7.8 |
| 6.4 | 7.9 |
Describe the effect of substrate concentration on the rate of this enzyme-catalysed reaction and explain why further increases in substrate concentration beyond a certain point do not increase the rate.