Lab: Diffusion Across a Semi-permeable Membrane Answers

The independent variable in this experiment was ✔ molecule sizemolecule colormolecule speed, and the dependent variable

was molecule shape✔ ability to diffuserate of diffusion.

The tubing contains ✔ starch solution Lugol’s solution starch solution and Lugol’s solution. The beaker

The tubing contains . The beakercontains .

The tubing contains . The beakercontains .

contains ✔ only Lugol’s solution starch solution and Lugol’s solution.

Initially, glucose was found only ✔ insideoutsideboth inside and outsideneither inside nor outside the dialysis tubing. After 15 minutes, a sample was taken. That sample showed that glucose was found

Initially, glucose was found only the dialysis tubing. After 15 minutes, a sample was taken. That sample showed that glucose was found the dialysis tubing.

If a test had been done of the solution inside the dialysis tube, what do you think the results would have been?

Analysis: Both glucose and starchNeither glucose nor starchOnly starch (larger molecules) ✔ Only glucose (smaller molecules) diffused though the semipermeable membrane.

Conclusion: Starch has a larger molecule size than glucose. So you can conclude that larger molecules are ✔ lessmoreequally likely than smaller molecules to diffuse across a semipermeable membrane.

Starch molecules are too large to pass through the tubing into the beaker. Which errors could have caused starch to appear in the beaker despite this fact? Check all possible errors.

Based on what you learned in the lab, why does your body need to break down starch into glucose?