The begining of the experiment where we -the students- were asked to put in 15ml of starch + glucose into the visking tube and 200ml of distilled water mixed with iodine solution in the beaker. Visking tube was put in to the beaker (as shown above) and left for about 40minutes.
Then, we were told to put 2ml of the solution from inside the visking tube into a test tube and another 2ml of solution from the beaker into a tues tube. Benedict solution was put into both the test tube...
...and was heated (as shown in picture) until...
Both the solution turns red. You may ask, "huh it's only one side red!" well...
Success!!! both turned red :D both test tube contains glucose as Benedict solution is to test the presents of glucose... OMG I still remembered WTF =.= What's wrong with me?
Conclusion: The movement of substances across a semi-permeable membrane depends on the it's size.