Biology

Osmosis & Diffusion Lab - Dialysis Tubing

1. Glucose was the substance that was going inside the beaker, and iodine was the substance

that went inside the bag.

2. The color changed inside the bag. In the beginning it was more of a clear color however in

the end the color changed into a dark blue/purple color. The other thing we noticed was that

the glucose amount in the beginning of the experiment in the beaker was 500++, but when

we measured the amount of glucose in the end of the experiment, we saw that it was 1000++.

This showed that the amount of glucose went up because it left the bag, and went to the

beaker.

3. The bag went from clear to a more darker color, blue. The molecules in the substances were

small enough to pass through the membrane. That is why the color changed in the bag. The

Iodine in the beaker was able to go pass through, and that is why there was a change of color

in the bag.

4. What we could do is weighting the amount of water before starting putting it inside the

dialysis tubing. Then after our experiment is done, we can weigh the water again. After that

we can do a comparison and checking if there was more water, or less.

5. Molecule size: Smallest- Largest

Water, KL molecules, glucose molecules, membrane pores, starch molecules

6. I believe the glucose and KL solution would cause the outside part to change colors. It would

be likely that the water would go from the bag into the beaker. The glucose would be mostly to

go inside the beaker just the same as it did in our experiment. The amount of glucose in the

beaker would also rise. As we discussed in the pervious question, the KL solution is one of the

smallest molecules, and it would come outside the beaker too.

Effect Of Molecule Size on Rate of Diffusion:

Hypothesis: In this experiment we are testing the effect of molecule size on rate of diffusion.

Variables:

Independent: Molecular size/weight ( quantitative)

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Dependent: Diffusion rate ( quantitate)...