Table 14. p-Nitrophenol standards
| Standard | Amount of p-Nitrophenol (nmol*) | Absorbance 410 nm |
| S1 | 0 | 0 |
| S2 | 12.5 | 0.206 |
| S3 | 25 | 0.385 |
| S4 | 50 | 0.831 |
| S5 | 100 | 1.676 |
*1 nmol = 1 nanomole = 1 x 10–9 mol = 0.000000001 mol
Table 15. Determination of p-nitrophenol produced using a high and a low substrate concentration based on p-nitrophenol standards.
| Cuvette | Standard That Is Most Similar | Amount of p-Nitrophenol Produced (nmol) |
| H1 | ||
| H2 | ||
| H3 | ||
| L1 | ||
| L2 | ||
| L3 |
- If you do not have a spectrophotometer, skip to Analysis of Results.
Quantitative Analysis of the Amount of Product Formed at Different Substrate Concentrations
- Blank your spectrophotometer with the S1 standard at 410 nm. Measure the absorbance values for your six cuvettes and record the absorbance values in Table 16 in the second column.
- Using the protocols you learned in Activity 1, calculate the amount of p-nitrophenol formed in all of your samples and record it in Table 16 in the third column.
Table 16. Determination of p-nitrophenol produced using a high and low substrate concentration based on a standard curve (similar to the one shown in Figure 8).
| Cuvette | Absorbance at 410 nm | Amount of p-Nitrophenol Produced (nmol) |
| H1 | 0.584 | 37 |
| H2 | 1.116 | 67 |
| H3 | 2.500 | 150 |
| L1 | 0.078 | 5 |
| L2 | 0.289 | 20 |
| L3 | 0.712 | 45 |
2.5 × 108 ÷ 1.8 = 150
