86%(7)6 out of 7 people found this document helpful
This preview shows page 1 - 3 out of 5 pages.
and they are submerged in water osmosis should occur increasing the mass of each dialysis tube.MaterialsFor Exercise 1A:•30-cm piece of 2.5cm dialysis tube•15 mL of 15% glucose/1% starch solution•String•250 mL of distilled water•4 mL of Lugol’s SolutionFor Exercise 1B:•Six 30-cm of presoaked dialysis tubing•25 mL of the following solutions:a)Distilled waterb)0.2 M sucrosec)0.4 M sucrosed)0.6 M sucrose
e)0.8 M sucrosef)1.0 M sucrose•Six beakers Filled with 250-mL of distilled water•StringProcedureFor Exercise 1A:1.Obtain a 30-cm piece of 2.5-cm dialysis tubing that has been soaking in water. Tie off one end of the tubing to form a bag. To open the other end of the bag, rub the end between your fingers until the edges separate.2.Place 15 mL of the 15% glucose/1% starch solution in the bag. Tie off the other end of the bag, leaving sufficient space for the expansion of the contents in the bag. Record the color of the solution (Table 1.1)3.Test the 15% glucose/1% starch solution for the presence of glucose. The teacher may have you do a Benedict’s test or use glucose Testape. Record the results (Table 1.1)4.Fill a 250-mL beaker or cup two-thirds with distilled water. Add approximately 4 mL of Lugol’s solution to the distilled water and record the color of the solution (Table 1.1). Test this solution for glucose and record the results (Table 1.1)5.Immerse the bag in the beaker of solution.6.Allow your set-up to stand for approximately 30 minutes or until you see a distinct color change in the bag or in the beaker. Record the final color of the solution in the bag, and of the solution in the beaker (Table 1.1)7.Test the liquid in the beaker and in the bag for the presence of glucose. Record the results (Table 1.1)For Exercise 1B:1.Obtain six 30-cm strips of presoaked dialysis tubing.2.Tie a knot in one end of each of the dialysis tubing to form six bas. Pour approximately 25 mL of each of the following solutions into separate bags:a)Distilled waterb)0.2 M sucrosec)0.4 M sucrosed)0.6 M sucrose e)0.8 M sucrosef)1.0 M sucroseRemove most of the air from each bag by drawing the dialysis bag between two fingers.