Problem
In a lab experiment using dialysis tubing as the artificial cell membrane, the researcher poured the solutions into the dialysis tubing, tied the ends, weighed them and placed each of them into their appropriate solution. After 60 minutes each of the dialysis tubing sacs we're removed from the solution, blotted dry and a final weight was recorded.
Beaker 1: water and 40% glucose
Beaker 2: 40% glucose and 40% glucose
Beaker 3: water and 10% NaCL
Beaker 4: water and 40% sucrose
• The sac inside beaker 1 gained 2 grams. Also the researcher did a Benedict's test for simple sugars and found glucose had moved through the dialysis tubing. Explain why the sac gained weight though the glucose was able to move across the tubing like the water.
• The sac inside beaker 3 gained 1 gram. Also the researcher did a silver nitrate test on the fluid inside the beaker and found that sodium chloride had moved out of the sac and into the beaker fluid. Provide one possible reason to explain why sac from beaker 1 gained more weight than the sac in beaker 3. Hint: look up molecular weights of the two
• The sac inside beaker 4 gained 4 grams. When the researcher performed the Benedict's test for simple sugars no sucrose was present in the fluid inside the beaker. Provide one reason why this sac gained more weight than the others