In this investigation, the concentration of glucose in the distilled water was measured at the start and then every five minutes - Edexcel - GCSE Biology - Question 5 - 2013 - Paper 1

The results show that there is an increase in the concentration of glucose in the distilled water over time. At the start (0 minutes), the concentration is 0.00 g cm³. This remains unchanged at 5 minutes, indicating that no glucose diffused through the visking tubing initially.

However, by the 10-minute mark, the concentration rises to 0.39 g cm³, and it continues to increase, reaching 0.79 g cm³ by both the 20 and 25-minute intervals. This indicates that glucose is gradually diffusing from the solution containing starch and amylase into the distilled water. The plateau observed at 20 and 25 minutes suggests that equilibrium may have been approached, where the diffusion rate into the distilled water matches the glucose concentration inside the visking tubing.