52 Cells, Membranes, and Transport Experimenting with an Artificial Membrane Dialysis membrane is used as a model system to understand the movement of molecules across a membrane. The basic setup is to have two solution various measurements including chemical tests, you can determine which molecules can move c r s separated by dialysis tubing Then, by performing the dialysis membrane. One of the solutions will be in a test tube, the open end of which is covered with dialysis membrane The other solution will be in a beaker. The test tube is inverted into the beaker to create the mem brane interface. The test tube will contain a solution of starch and ghcose. The beakes will comtain a solution of iodine. Before setting up, read through all of the instructions in this section. Next fill in the Prediction, Reasoning, and How to Test? columns of the table Experimenting with an Artificial prepare the materials you will need to test your predictions. Dialysis tubing н,о lodine Rubber band Figure 6 Experimental set-up. 1. Use a wax pencil to mark 1 cm from the bottom of the test tube, and then 1 cm up from that. 2. Use these marks to add 1 mL 20% sugar solution and then 1 mL 1% starch solution to the test tube Set up the test tube. (1 cms 1 mL) 3. Cover the end of the test tube with a single piece of wetted dialysis membrane. To get a single piece fingers to open the cylinder. Cut the membrane to obtain a single layer of membrane to use. 4. Secure the dialysis membrane in place with a rubber band. 5. Test for leaks by inverting the test tube over a beaker. If necessary, adjust the membrane and bands. of dialysis membrane, first soak the flattened cylinder of membrane and then rub it between your Set up the beaker. 1. Place the test tube upside down into the beaker 2. Add water to the beaker until the membrane is just covered. The less water you use, the faster diğusion will occur. (See Factors That Can Affect the Role of Diffusion.) 3. Add iodine solution to the water in the beaker and swirl until the water is uniformly a pale orange (5 drops more or less, depending upon the strength of the iodine solution). Allow the setup to remain for about 15-45 minutes, or until you can see a color change. Fill in the Results and Conclusions column of the table Experimenting with an Artificial Membrane enting with an Artificial Membrane Prediction Reasoning How to Test Glucose Movement from test tube into beaker? StarchMovement from beaker to test tube? lodine Movement from beaker into test tube? Water Net movement from beaker into test tube? Or from test tube into beaker?