2 A student investigated the diffusion of substances through Visking tubing, an artificial membrane which has some of the properties of cell membranes. The student made a bag of Visking tubing as shown in Fig. 4.1. top of syringe. elastic band Visking bag. knot bag filled with starch solution (a) (1) Explain these results. and placed into a test-tube of water Fig. 4.1 test-tube starch solution water The student added some iodine solution to the water in the test-tube. After 30 minutes at room temperature, the contents of the Visking bag were stained blue-black, but the water outside remained a yellow colour.?​