Question

Some students investigated the effect of pH on the action of the enzyme trypsin. Trypsin breaks down a protein found in milk. This turns the milk into a clear, colourless solution. The students set up five test tubes. Each test tube contained trypsin and milk at either pH 5, 6, 7, 8 or 9. The students then timed how many minutes it took for the milk in each test tube to turn colourless. Trypsin works best at pH 7.8. Predict the results of this investigation.

Answer 1

Based on the information provided, here's a prediction for the results of the investigation on the effect of pH on the action of trypsin:

1. **pH 5:** At this acidic pH, trypsin's activity is expected to be significantly reduced. It may take a longer time for the milk to turn colorless or may not happen at all, as trypsin typically works optimally in a slightly alkaline environment.

2. **pH 6:** Trypsin's activity is still likely to be reduced compared to pH 7.8, but it might work better than at pH 5. The time taken for the milk to turn colorless would probably be longer than at pH 7.8.

3. **pH 7 (neutral):** This pH is closer to the optimum for trypsin (pH 7.8). Trypsin's activity should be relatively efficient at pH 7, and the milk may turn colorless relatively quickly compared to the other pH levels.

4. **pH 8:** As the pH becomes more alkaline than the optimum for trypsin, its activity may start to decrease. It might take longer for the milk to turn colorless compared to pH 7.8, but it could still be more efficient than at lower pH values.

5. **pH 9:** At this highly alkaline pH, trypsin's activity is expected to be significantly reduced. Similar to pH 5, it may take a longer time for the milk to turn colorless or may not happen at all.

In summary, the results are likely to show that trypsin's activity is optimal around pH 7.8, and its effectiveness decreases as you move away from this pH, both in the acidic and highly alkaline directions.