To visualize diffusion of molecules across a semipermeable membrane
To determine which molecules were permeable to the dialysis tubing
To relate the diffusion of molecules across the dialysis tubing to diffusion across a plasma membrane
To identify (3) factors that contribute

1.
a.
Most hypothesized the following:
Glucose moves out of the dialysis bag b.
c.
Starch moves out to the dialysis bag
Iodine moves into the dialysis bag
“Why did people think this would happen?”
2. A few hypothesized that starch molecules would not move out of the dialysis bag.
“Why would a few think this?”

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
Starch diffused out or stayed in bag – Iodine
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
Iodine reacts with starch and turns blue-black
Observe setup and complete Table 1
Glucose diffused out of bag – Benedicts
Solution
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
Benedicts reacts with glucose and turn organge.
Add about two droppers of beaker water to test tube



Add Benedicts to test tube to make water blue
Place in hot water bath
Record observation in Table 2
Complete Analysis Questions #1-5

This is after the dialysis bag that was filled with a glucose and starch solution looked like after 60 minutes.

This is what the setup looked like after 24 hours.

This is a tube of beaker solution and Benedict’s solution. Note the orange color that looks like carrot juice. Yum, yum!